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New Year's Resolution: Full Disk Encryption on Every Computer You Own

231 points by tobiasbischoff 15y ago

deleted 15y ago
[deleted]
- jiggy2011 15y ago
  I imagine in many cases that's exactly what they do, assuming they even bother to format if they want to get rid quickly. A more enterprising thief however might wonder if there's something else there, even if he's just after naughty pictures. Assuming you haven't used encryption it's very easy to get data off a computer if you are even a little bit technical. Simply take the disk out and insert it into another computer or just reboot the same computer using a Linux live CD, all the files and everything from the NTFS partition will just be displayed and available. No need for the administrator password at all, regardless of what file permissions were set.
- mike-cardwell 15y ago
  "I have always thought that the only reason you would need full disk encryption on a computer is if you was doing something illegal." Did you even read the article? It mentions several legitimate reasons why you would need to use encryption for perfectly legal reasons. It still surprises me hear people who are intelligent enough to use the Internet come out with the, "if you've nothing to hide" argument. EDIT: The information I claimed was in the linked article, was actually in the whitepaper, linked to from the article. I will quote the relevant passage below. It amazes me that anyone would not be able to come to this conclusion independently though: "For doctors, lawyers, and many business professionals, these border searches can compromise the privacy of sensitive professional information, including trade secrets, attorney- client and doctor-patient communications, research and business strategies, some of which a traveler has legal and contractual obligations to protect. For the rest of us, searches that can reach our personal correspondence, health information, and financial records are reasonably viewed as an affront to privacy and dignity and inconsistent with the values of a free society."
  - goblin89 15y ago
    Not to argue with your points (business data is sensitive stuff), but another link from the article leads to this: > For maximum security make sure you are alone and close the curtains. Write on a hard surface - not on a pad of paper. After you memorize your passphrase, burn your notes, pulverize the ashes and flush them down the toilet. That is quite a paranoid's hell. =) Full-disk encryption may just provide false sense of safety, as we store lots of data in the cloud, where even strong passwords do not guarantee that nobody will get access to the data. IMO for one to be 100% sure that nothing could go wrong one should not store anything anywhere.
    - icebraining 15y ago
      Full-disk encryption may just provide false sense of safety, as we store lots of data in the cloud, where even strong passwords do not guarantee that nobody will get access to the data. You can store an encrypted file "in the cloud", though. A truecrypt volume with a keyfile should be essentially uncrackable. Of course, then you can only use the service as a dumb data storage.
- fletchowns 15y ago
  I think we would all be a little amazed and horrified at the actual amount of sensitive identify information is floating around on thumb drives and usb hard drives.
- thibaut_barrere 15y ago
  I use crypted vaults for all my customer projects. I couldn't sleep well otherwise.
  - daeken 15y ago
    I use FDE and then encrypted vaults for each project. Even if my computer is lost/stolen when it's on or asleep and the FDE does nothing, I can be assured that the vast majority of the sensitive data is safe.
    - thibaut_barrere 15y ago
      I'm adding FDE too :) I use Knox for Vaults (on Mac), what do you use out of curiosity?
      - daeken 15y ago
        Knox on OS X (what I use for day job work) and Truecrypt on Windows. PGP Desktop for FDE.
      - sitkack 15y ago
        Knox is a better UI for the bultin in folder encryption on OSX?
        thibaut_barrere 15y ago
        see http://help.agilebits.com/Knox/why_knox.html http://help.agilebits.com/Knox/why_knox.html
        sitkack 15y ago
        Cool. I already do something similar with encrypted sparseimages, I will give this a try.
tobiasbischoff 15y ago
On OSX with Lion - there is no excuse http://osxdaily.com/2011/08/10/filevault-2-benchmarks-disk-encryption-faster-mac-os-x-lion/ http://osxdaily.com/2011/08/10/filevault-2-benchmarks-disk-e...
- nonane 15y ago
  Have you noticed crashes and general instability on OS X Lion + Filevault 2? We've tried it on a Core2Duo Macbook Pro (early 2007) and MacBook (Mid 2010). We've seen lots of OS crashes (Macbook) and general performance issues when running XCode (Macbook Pro). We're also running virtualization software on the Macs (Parallels and VMWare) - I'm not sure if they're interacting with Filevault 2 (shouldn't be). Just wonder if anyone else has noticed this.
  - benologist 15y ago
    I use it on a 2011 Air and Mini without problems, and I'm just about always in Parallels on both machines.
  - maukdaddy 15y ago
    I use Lion's Filevault 2 on an early 2009 MBP and have not had any crashes or stability problems at all. FV2 on Lion is light years ahead of the broken Filevault 1 (Snow Leopard) implementation.
  - tobiasbischoff 15y ago
    no i have no problems. macbook air 2010 w/ lion + file vault active - no crashes or instability. i do time machine backups on a regular basis and work with Xcode, photoshop, iWork, vmware fusion - never had any problem.
- Tichy 15y ago
  Does it now play well with Time Machine?
  - mark_l_watson 15y ago
kia 15y ago
Microsoft BitLocker in its most secure mode is the gold standard because it protects against more attack modes than other software. Unfortunately, Microsoft has only made it available with certain versions of Microsoft Windows. Though MS says that BitLocker doesn't have back doors [1], I wonder how true this actually is... [1] http://blogs.msdn.com/b/si_team/archive/2006/03/02/542590.aspx http://blogs.msdn.com/b/si_team/archive/2006/03/02/542590.as...
- sliverstorm 15y ago
  Do MS developers have a track record of bald-faced lies that I'm unaware of?
  - dhbanes 15y ago
    http://en.wikipedia.org/wiki/NSAKEY http://en.wikipedia.org/wiki/NSAKEY
- slowpoke 15y ago
  Exactly. Trusting proprietary, closed source software (in other words, a third party) for encryption is missing the point of encryption so hard, it's not even funny.
  - jazzyb 15y ago
    To be fair, I trust TrueCrypt because it's "libre" and "open", but I've never looked at the source code myself. I trust that other people more knowledgable than me have taken a look at it, but if there is indeed a backdoor in it, then it will look on the surface like the most innocuous bug in the world. Don't get me wrong: I understand and appreciate your point, but I honestly don't know how most of us using TrueCrypt (e.g. me) are any better off than those who use a proprietary solution. The only difference I can see is any backdoors in TrueCrypt or PGP must be better hidden.
    - slowpoke 15y ago
      While you are basically correct, the mere ability to check the source yourself and possibly be able to find (or even fix) said bugs-which-could-or-could-not-be-cleverly-hidden-backdoors puts it leagues ahead of any proprietary solution, where there is never any way to be sure there isn't just something like a void force_decrypt(string company_master_password)[1] in there. And to be perfectly honest, I'd rather trust the FLOSS crowd who checked TrueCrypt and other more or less popular encryption tools probably hundreds, if not thousands of times than trust the development team of a company refusing to release the source of their software. [1] Yes, I am kidding, but I hope you catch my drift.
codesuela 15y ago
I got myself an SSD for Christmas and that is why I moved off full disk encryption on home computer and instead encrypt almost everything except the system. However I've turned off the page file and I'm trying to set up pre boot authentication for non system volumes. On another note, I plan to slowly switch to Ubuntu and I wonder how secure the home folder encryption is?
- mike-cardwell 15y ago
  There's nothing stopping you using FDE on an SSD...
  - codesuela 15y ago
    FDE on a SSD negates the gained speed advantage
    - mike-cardwell 15y ago
      Does it? Even if you have a CPU with AES-NI instuctions like an Intel Core i5 or i7?
      - codesuela 15y ago
        unfortunately yes, see http://blog.siyuz.net/2010/11/17/truecrypt-7-0a-fde-on-ssd/# http://blog.siyuz.net/2010/11/17/truecrypt-7-0a-fde-on-ssd/#
        arthurschreiber 15y ago
        I encrypted my SSD using BitLocker, and for me, the performance hit is not really noticable in my day-to-day work (programming + running a virtual machine). Your SSD will still be A LOT faster than a regular, unencrypted HDD. But YMMV.
        polshaw 15y ago
        This case is only relevant to SSDs with a sandforce controller, however -- as (only) the sandforce controller compresses data for increased speed, which cannot be done with encrypted data.
wazoox 15y ago
None of my current computers is powerful enough for that without it being a serious hassle. And I'm pretty sure it will drain my laptop battery much faster...
- thibaut_barrere 15y ago
  Which OS do you use? On Mac OS X I use Knox; my 2006' MBP doesn't have any issue with that.
  - wazoox 15y ago
    I'm running Linux everywhere, and Snow Leopard on my MacBook. I find the MacBook a bit slow at time (mostly because of the 2GB RAM I guess). I still use an ancient Athlon64 single core with 1GB as my main desktop, though :)
- sitkack 15y ago
  It looks like many people assume this to be so but haven't done the benchmarks. FDE is going to be a much smaller hit than say anti-virus software. Encryption routines have been highly optimized into the multi gigabytes per second range.
  - wazoox 15y ago
    > FDE is going to be a much smaller hit than say anti-virus software. But I don't run any anti-virus, this is even one of the good reasons why I stopped using windows aeons ago. I tried LUKS with AES a few years ago, and though the performance was good it comes with a really significant hit.
- RexRollman 15y ago
  I have tested Windows 7 with both Bitlocker and Truecrypt, and Arch Linux with with LUKS, on my four year old Dell e520 (a 1.8ghz Core 2 Duo 6300 PC with 4GB of RAM). I didn't notice any real performance difference with FDE enabled, although I am sure a proper benchmark tool would have shown something.
- 15y ago
ck2 15y ago
It's sad we need encryption mostly for protection from not criminals, but our own government for even trivial data. What freaks me out most these days is how easily people fall into the belief that "oh well traveling is not a right so you have to give up rights when you fly or drive anywhere". No, if you are a citizen of the United States and unless you are actually crossing a border, you should have the unqualified protection against unreasonable searches, especially without warrants. I also don't accept the "well it's worse in other countries, be happy you are not there" argument. This country is not even 250 years old. The laws we made are pretty fundamental and not old at all. It's not some kind of game where they should be allowed to dance around the edges to break them.
- flipbrad 15y ago
  To be honest, I don't see why national borders are so strongly part of the equation. I suppose that depends on your worldview. I live within the Schengen Area, and to me it seem patently obvious that most 'bad things' in the world are hardly affected by national borders. They're typically supra-national (climate change, credit crunch, cracking, etc) or intra-national (most crime, etc. I don't mean to argue for more checks / security measures, overall, but why do you want them to be focused at the border?
  - icebraining 15y ago
    Drug trafficking and illegal immigration?
    - Willwhatley 15y ago
      Human trafficking is the new drugs. Apparently it's enormously more profitable to import sex workers and keep them in a kind of narcotic/whatever assisted slavery, because of the reuse of the person vs. the consuming nature of the drug.
      - flipbrad 15y ago
        We're getting way off topic but I'd be interested to see a source for that claim. I imagine that the costs associated with a prostitute (food, shelter) would be significantly higher than those associated with a stock of inert crystalline powder, pills, or resin. Even if nominally borne by the prostitute, those greater costs still reduce the profitability of the overall enterprise.
code4pizza 15y ago
I wonder if there would be significant environmental implications if everyone switched to full disk encryption... Does this impose a significant processor load and does that translate to greater power consumption?
- justanotheratom 15y ago
  I wouldn't worry too much about it. There is a fixed CPU overhead, but negligible. http://www.tomshardware.com/reviews/bitlocker-truecrypt-encryption,2587-9.html http://www.tomshardware.com/reviews/bitlocker-truecrypt-encr...
- sitkack 15y ago
  An idling CPU and a slightly loaded CPU use about the same amount of energy. I think my Q6600 quad used 190W @ idle and running full tilt cpu (ray tracing) it was using 220W. For FDE it depends on how much IO you are doing. I doubt it will make even a 0.01 difference in your daily power consumption.
  - mikeash 15y ago
    I don't think so. On my laptop, fully loading the CPU takes it from silent to screaming fans in about two minutes. That's clearly a big change in heat production and therefore power consumption.
    - sitkack 15y ago
      You should use a kill-a-watt and measure it. Probably less than you think. Laptops already on the edge of their thermal envelopes, anything above their low steady state (browsing, listening to music) will cause the fans to spin.
      - mikeash 15y ago
        The battery time remaining will also drop by a factor of 4 or more. This is large enough that I don't think a more precise instrument is needed to determine that the effect is significant.
jrgifford 15y ago
Unfortunately, the amount of time I spend running/breaking the development version of Ubuntu prohibits full disk encryption, but I do have /home encrypted. Is that "good enough"?
- morsch 15y ago
  That's what I intend to do the next opportunity I get. Your swap space could still leak confidential information, though.
  - jrgifford 15y ago
    I'm willing to risk that since I rarely use any of my swap.
    - slug 15y ago
      You can and should encrypt your partition, since your home key might end up there. https://help.ubuntu.com/community/EncryptedFilesystems https://help.ubuntu.com/community/EncryptedFilesystems If you want hibernate to work you can use uswsusp for example: https://we.riseup.net/debian/encrypted-swap https://we.riseup.net/debian/encrypted-swap Sleep always works, but as mentioned above, your key will be in memory...
      - jrgifford 15y ago
        Interesting.... I think i'll stick with user directory encryption, but thanks for those links.
        slug 15y ago
        Well, I use /home with luks on some machines and user directory (encfs) on others, but have all of them with swap encrypted or no swap partition at all. Since the keys/other private info might leak there, you are not doing it right, unless you have sysctl swappness level set to 0. Not only that, /tmp and other temporary directories might also be another leaky place...
SickAnimations 15y ago
My system triple boots into OS X, Windows and Ubuntu. I have a home partition, formatted in HFS+. What would be the best strategy for me to use? Should I just encrypt the home volume using something cross-platform like TrueCrypt, or is it practical (an maintainable) to do full-disk encryption in such an environment? My home partition has very sensitive data and I've been putting off creating a TrueCrypt container for this data.
- nonane 15y ago
  This is probably not answering your question but a possible solution is to switch to using OSX 100% of the time and then use Parallels/VMWare/VirtualBox to virtualize Windows and Ubuntu. It's much more practical than having to worry about partitions / boot volumes and general sharing problems. This way you can even encrypt your entire OS X volume and not use encryption on the VMs.
- m3koval 15y ago
  I'm also dual booting OS X and Ubuntu with a shared home partition formatted as HFS+. Getting the encryption to work nicely in Linux sounded pretty easy, but I couldn't figure out how to do it in OS X. My current solution is to store anything particularly sensitive in a TrueCrypt file...obviously not the best solution. Out of personal interest: Did you get Linux to mount the HFS+ partition with R/W access with journaling enabled? I am also curious if you make any progress with encrypting the entire partition.
Jach 15y ago
If you go full disk encryption with TrueCrypt, make sure you look into their Hidden OS feature as well. A judge may be able to order you to give up the decryption key to the OS when accessing the drive prompts for one (last I checked the precedent is still somewhat shaky), because while they can't know what's being encrypted they can infer something readable is. They can't prove the existence of a Hidden OS, though, so your 'real' encrypted area is just noise and can't be legally proved anything else so a second key can't be demanded.
- hetman 15y ago
  Might look odd if none of the files on the decoy have been modified in the last 6 months - logging in to do this regularly and in a believably meaningful way seems like a burden. The good news is unless you're an international crime lord, it seems unlikely there will be anyone on hand in the court to make this kind of leap (not a lawyer so that guess could be way off though).
  - jpdoctor 15y ago
    An automated update of the decoy would be a good addition to such software.
    - fl3tch 15y ago
      Not sure exactly how this would be implemented, but it sounds like a bad idea, since they would just wait for your automated updater to decrypt the decoy. Even if it was in some limited fashion, the encryption key would be in RAM, so it would be as vulnerable as any running system. (BTW, if you're worried about a state-level adversary, that means you should always turn off your computer when not using it, and wait a few minutes before physically leaving it to prevent a cold boot attack)
      - esrauch 15y ago
        Well, the point of the decoy i that you don't care if they can access it isn't it?
brador 15y ago
I just use two RAIDed NAS boxes, one as a long term, large file media/data store and another for small files on SSD RAID. All my comps are now dumb terminals, booting an OS and software. Works well and was surprisingly cheap for what is essentially a complete, hassle free system.
josscrowcroft 15y ago
Enlightening (and scary) stuff. Encryption is great but won't save you if they ask for your password (honestly, I'd prefer to give them the password and circumvent using online storage.) With that in mind - what advice would all you security buffs have on the best way to back up your hard drive to an online disk? Specifically using a basic hosting account as opposed to SAAS or cloud service?
- po 15y ago
  I actually trust tarsnap more than setting up a host and having to maintain it: http://www.tarsnap.com/ http://www.tarsnap.com/
  - josscrowcroft 15y ago
    Looks very interesting, as services go. For this kind of thing, I'm strangely less inclined to trust a slick-looking, well-designed and heavily-marketed backup "solution".. If I do fork out for a service, I would probably rather go with the kind of company that has as their tagline: "Online backups for the truly paranoid", like them. Pricing's not a killer either.
    - po 15y ago
      This service is run by a long time hacker news user and security researcher cperciva. Read his stuff: http://news.ycombinator.com/user?id=cperciva http://news.ycombinator.com/user?id=cperciva http://www.daemonology.net/blog/ http://www.daemonology.net/blog/
    - merijnv 15y ago
      The reason I trust (to the extend I trust anything on this planet) Tarsnap is that Colin Percival (the creator) is a cryptographer and the FreeBSD security officer. Leading to me have a higher confidence in him than most of the other "secure" backup services I have seen.
      - josscrowcroft 15y ago
cafebabe 15y ago
Next year's resolution: Getting out of holding / prison without compromising the passphrase to your fully encrypted disk.
justatdotin 15y ago
do most people really have private information on their computer? I don't think I do ...
- baq 15y ago
  depends what you consider private. for me, everything is private as long as i don't put it online consciously. yes, even that photo of me sitting on a chair.
casca 15y ago
It's nice that computers are now powerful enough that full disk encryption is almost performance-neutral. But realistically, if they want your data then they can get it. Spear phishing works very well and if not, there's always indefinite detention. Technology is only a small part of the solution to warrantless border searches.
- mike-cardwell 15y ago
  What encryption gives you is choice. If you don't use it, then you never have the choice of whether or not to give up data. The choice is taken for you. If you use encryption there are many attackers that you will be able to prevent being able to access the data.
DanielBMarkham 15y ago
I'm not an expert on security, but I do know a bit about human nature. I'd suggest a 2-level encryption scheme. Perhaps FDE and a BIOS password as level 1, and then a futher encrypted area of your HD as level 2. Why? Because this allows you to appear to be cooperating with any request to look at your computer. Simply type in the level 1 stuff and demonstrate the system booting up. I bet 9 times out of 10 whoever is checking you over will stop right there: it looks a lot like compliance. If they keep pushing for total access to your data simply say "no" Whereas if you say "no" to begin with, you're likely to attract more attention than if it appears you have nothing to hide. In many cases people are working jobs where they only have so much time to check things -- unless there appears to a be a person with a problem, in which case they can take all day with you. So help them out. Give them something to ask you for that you can produce. Then everybody can move along and it's not a problem for anybody.
- nohat 15y ago
  Truecrypt has a hidden OS option. It does sound like some work, however.
- tocomment 15y ago
  Once you boot up and log in couldn't they see your whole system.
  - culturestate 15y ago
    Not if your secondary partition isn't mounted automatically. It's not a stretch to assume that customs agents (or whomever) aren't going to look for unmounted partitions when the computer is booting and running normally.
trotsky 15y ago
The feds and other serious folks are pretty careful these days not to turn off anything until they've had forensics evaluate the situation. And not just because of FDE, memory analysis very frequently yields the best evidence due to it's timely and overlooked nature. Since most encryption systems retain their keys during lock and sleep, unless you usually leave your system powered off I wouldn't count on being afforded much privacy if you're interesting enough to bother. That said I still use it on both of mine and definitely suggest it, it's a very small performance penalty for what will be a godsend if your laptop turns up lost or stolen. https://code.google.com/p/cryptsetup/ https://code.google.com/p/cryptsetup/ It's an excellent precaution against the much more mundane and common threats like loss or theft though
- fl3tch 15y ago
  If you're worried about a state-level adversary, then yes, you should always turn off your computer when not using it. They could still be spying on you and wait until you turn it on to kick down the door. There are people who have thought about these things, too. One suggestion is a dead man's trap, like a pad that you sit on, so if the door gets kicked down (or they snipe you from outside the window), as soon as you stand up (or fall off the stool) it scrambles RAM and shuts down the system. That's a super high level of paranoia, but still makes encryption useful.
  - epochwolf 15y ago
    You could just hold down the power button on your computer for 4 seconds and require a password to boot the system.
    - pyre 15y ago
      That depends on how quickly they can get guns pointed at you once the door is kicked in.
      - epochwolf 15y ago
        Okay, then you can set up your system to do a force shutdown if the power button is hit. If you're on a desktop, have a power strip near your foot so you can kick the toggle switch if the door comes down. (Or have a big red kill switch wired into the power supply on the front of the case.) The latter option probably won't earn you any favors with the judge or the jury.
finnw 15y ago
I am not convinced by one of the quiz answers: > Our calculations confirm that a relatively short series of truly randomly chosen English dictionary words is secure; many people find these somewhat more memorable. Above we used "In the jungle! The mighty Jungle, the lion sleeps tonight!" The important thing is to choose enough words and to choose them in a random un-guessable way, such as by changing the spacing, punctuation, spelling, or capitalization. The problem with this example is that the 10 words are not chosen independently. Type "in the j" into a google search box and the whole phrase will appear in the drop-down box. So the entropy for the choice of that phrase is about lg2(37^8) or about 42 bits. So an approximation of the total entropy is: Choice of source phrase = lg2(37^8) ~= 41.7 bits Choose one of the 10 suggestions from the drop-down box = lg2(10) ~= 3.3 bits Permutation of words = lg2(10! / 2! / 3!) ~= 18.2 bits Spacing (assume each word may independently be precedeed by a space with probability 0.5) =10 bits Punctuation (each word may be independently followed by '!') = 10 bits Capitalization: independently choose one of {lowercase, camelcase, uppercase) for each word = lg2(3^10) ~= 15.8 bits Total so far: 98 bits. Now consider the third option: a mixture of 16 independently-chosen letters, numbers and symbols. Assume most ASCII characters are available (lets eliminate single quote, backslash and $ which cause problems for some web apps) and we have lg2(92^16) ~= 104.4 bits, which wins.
- dlytle 15y ago
  The point is that "In the jungle" etc can actually be reliably remembered by a large portion of the population, whereas 16 independently chosen letters/numbers/symbols usually can not. Humans are great at remembering phrases, quotes, etc. Think about how widespread referential humor is, where the joke is just a reference to/quote from another work. That's something the brain is great at. Random or semi-random jumbles of letters? Not so much.
  - Cyranix 15y ago
    In illustrated fashion: http://xkcd.com/936/ http://xkcd.com/936/
phillmv 15y ago
What's the performance penalty like? That's pretty much the only thing holding me back.
- tcas 15y ago
  Pretty minimal. If you have TrueCrypt installed you can run a benchmarks of various algorithms. It's especially fast if you have a modern processor with AES-NI (hardware AES instructions) -- I get around 1GB/s Encrypt/Decrypt using AES on a Core i5.
Havoc 15y ago
I'm concerned about privacy too but none of the worrisome areas would be improved by FDE. Facebook/Google, tracking, keyloggers etc is where the main problem lies.
quinndupont 15y ago
Does anyone have any thoughts on Apple's File Vault? I assume the crypto is perfectly fine, but I worry about bugs destroying my data.
- quinndupont 15y ago
  Apparently FileVault has been much improved in OS X Lion: http://www.maclife.com/article/howtos/how_use_filevault_and_time_machine http://www.maclife.com/article/howtos/how_use_filevault_and_...
samstave 15y ago
What about on my mobile? I am not aware (as I havent looked) of any encryption available to the data on my iPhone, or MyTouch 4G. Further, I use Gmail - I have zero expectation of privacy from google. I also store all my important docs for work and personal on DropBox. What will I gain from encrypting my laptop? aside from it being stolen/lost - I dont see any added security/benefit from doing this. I am not trying to be obtuse - but can one explain to me why I would want to do this, other than expressing my tech savvy?
- tjoff 15y ago
  Android ICS and Honeycomb allows for your data to be encrypted. Don't use gmail and don't use dropbox for unencrypted files ;) But seriously, the risk of your laptop being stolen or lost is a huge incentive for encrypting it. I feel much better knowing that the worst that could happen with my laptop is that i loose it (stolen/lost/dropped). I wouldn't wan't to be uncertain whether anyone had access to my personal files if it got lost and the data I have on it is more valuable than the hardware (and I'm still a student...). For anyone that is tech savvy I see no reason not to do FDE. Okay, two exceptions. Loosing TRIM support on SSD-drives and travelling to/from countries that feel they have the right to inspect the content of my laptop and that might frown upon the fact that it is encrypted.
- culturestate 15y ago
  iPhone data is encrypted by default - remote wipe works by destroying the key. Unfortunately, the key is obviously only protected by a user's passcode, if they've even set one. The 4-digit pin codes have been shown to be broken, but I've not seen (maybe I missed it?) evidence of those with alphanumeric passcodes being compromised.
  - rdl 15y ago
    The issue is that I can conduct an unlimited-attempts brute force attack against the passcode. I can do about 10 per second on an iPhone 4S, but I do need access to the machine, unless I'm willing to crack open the iPhone and do a destructive hardware attack. At 10 per second, I feel ok with an 8-10 character numeric passphrase, or a 7-8 character lowercase-only passcode. I just wish the iPhone had some intelligence about adaptive locking -- lock faster when it's outside my home/car, don't go from unlocked to locked very fast, if at all, if docked in secure places inches from a 9mm. Or pairing with an RF device attached to me, like the Blackberry CAC reader.
paulhauggis 15y ago
This is all good, until you get any kind of disk corruption. Good luck getting any of your data back.
- outworlder 15y ago
  That's why you should have up-to-date backups.
  - paulhauggis 15y ago
    but then couldn't people still get to your unencrypted data (through your backups)?
    - culturestate 15y ago
      If you're doing FDE, you should be encrypting your backups as well. It can be relatively trivial, depending on your backup setup.
      - jodrellblank 15y ago
        This is all good, until you get any kind of disk corruption. Good luck getting any of your data back.
        culturestate 15y ago
        If my encrypted disk becomes corrupted and then corrupts my unencrypted backup, what's the difference?
        jodrellblank 15y ago
        A good backup, e.g. Time machine, lets you restore feom before the corruption. A backup on an encrypted disk risks the entire backup volume being corrupted and unusable in one go, thus making it a very brittle backup. I'm assuming that a corrupted encrypted file is totally unusable here, and now that I think more about it I'm not sure - encryption with chained blocks would mean errors have a larger affect than just at the error site, wouldn't it?
nohat 15y ago
One thing that worries me is how difficult it makes it if you get some data corruption. For example, I had a hardrive that had full disk encryption start to fail, and found pulling the data off much more difficult because I had to decrypt the whole lvm to get any access. I'm actually not confident how exactly corruption maps from cyphertext to plaintext in various modern crypto systems. I would guess that you would get out gibberish though.
- spindritf 15y ago
  I would rather back my data up than hope to retrieve it from a corrupted fs or, worse, a failing disk.
pasbesoin 15y ago
Can anyone comment on the speed/performance of TrueCrypt, EncFS, and similar on older systems, e.g. a 5 - 7 year old laptop? I'm considering carrying a "sacrificial" machine in case it is, um, "indefinitely detained", but I'm uncertain what kind of a performance hit full disk (or partition -- though I'm inclined to encrypt the entire disk) encryption will incur. (I currently have Core Duo and P4 candidates for the job.)
- tjoff 15y ago
  Truecrypt has a simple benchmark that you can try (and I think it has a portable installation option so you don't even have to install it on the system to try it out). My core duo 1.6 GHz laptop gets about 60 MB/s of AES encryption/decryption speeds on battery (which I think reduces the clock to 1 GHz). I consider the impact negligible. However if you have an SSD in your system and do full-disk-encryption you will loose potential TRIM-support which can have a significant performance penalty depending on drive.
  - pasbesoin 15y ago
    Thank you for the response. These are both "spinning plates" machines. Part of what would keep their loss a minor financial hit. I wonder whether the dual cores help significantly. (As I'm more inclined to make the P4 the sacrifice.) However, if your observation is that the perceived impact is "negligible", this encourages me that it will be acceptable, if more significant, on the P4. I hadn't noticed the benchmark utility you describe. I'll have a look for/at it. Thanks!
bengl3rt 15y ago
Unfortunately, full-disk encryption absolutely kills SSD performance because it makes the data look random (i.e. incompressible). It will wear out the SSD much faster than using it without would, because the hardware compression unit in the controller can sometimes achieve 8:1, and therefore have to rewrite only 1/8th of the NAND cells that it otherwise would.
- gojomo 15y ago
  I think you're right on the effect but wrong on the implied grave magnitudes "absolutely kills" and "much faster", because: • not all SSDs even have hardware compression • modern workloads have less highly compressible data than in the past: large-media formats include their own compression, and bulk data processing often does its own application-level compress/decompress on store/load I'd be interested to see any benchmarks that quantify the speed/lifetime hit that whole-disk encryption might cause for SSDs, but my hunch is that the effect would be slight in normal scenarios.
  - culturestate 15y ago
    Anand benchmarked FileVault(1) and his conclusion was "Overall the hit on pure I/O performance is in the 20 - 30% range. It's noticeable but not big enough to outweigh the benefits of full disk encryption." 1. http://www.anandtech.com/show/4485/back-to-the-mac-os-x-107-lion-review/18 http://www.anandtech.com/show/4485/back-to-the-mac-os-x-107-...
    - kgtm 15y ago
      Yes, but that result is most likely on a Sandforce-powered SSD, which sports different transfer speeds based on the payload (compressible/incompressible). Like the GP notes, this is not a problem with SSDs in general.
      - culturestate 15y ago
        That benchmark is with a stock Apple SSD, which IIRC are not Sandforce-based. To be clear, I'm actually in agreement with Anand and OP - the benefits of FDE far outweigh the consequential I/O hit.
dicroce 15y ago
I did this over a year ago and am very happy. I use TrueCrypt. I have not noticed any slow downs (even for gaming)... That said, you should probably not do this if your drives are failing (or you tend to suffer a lot of disk failures).
rogerbinns 15y ago
So how do you encrypt a home server? Any device that has to be bootable without human intervention will have to store the encryption keys on the device somewhere making the encryption merely obfuscation. It is possible for "swap" RAM to be encrypted on Linux and it could generate a random per boot key, also being a form of obfuscation. https://lkml.org/lkml/2011/12/28/69 https://lkml.org/lkml/2011/12/28/69
deleted 15y ago
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bumbledraven 15y ago
It's great to see the EFF recommending http://diceware.com http://diceware.com for secure passphrase generation.

231 points by tobiasbischoff 15y ago

deleted 15y ago

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jiggy2011 15y ago
I imagine in many cases that's exactly what they do, assuming they even bother to format if they want to get rid quickly. A more enterprising thief however might wonder if there's something else there, even if he's just after naughty pictures. Assuming you haven't used encryption it's very easy to get data off a computer if you are even a little bit technical. Simply take the disk out and insert it into another computer or just reboot the same computer using a Linux live CD, all the files and everything from the NTFS partition will just be displayed and available. No need for the administrator password at all, regardless of what file permissions were set.
mike-cardwell 15y ago
"I have always thought that the only reason you would need full disk encryption on a computer is if you was doing something illegal." Did you even read the article? It mentions several legitimate reasons why you would need to use encryption for perfectly legal reasons. It still surprises me hear people who are intelligent enough to use the Internet come out with the, "if you've nothing to hide" argument. EDIT: The information I claimed was in the linked article, was actually in the whitepaper, linked to from the article. I will quote the relevant passage below. It amazes me that anyone would not be able to come to this conclusion independently though: "For doctors, lawyers, and many business professionals, these border searches can compromise the privacy of sensitive professional information, including trade secrets, attorney- client and doctor-patient communications, research and business strategies, some of which a traveler has legal and contractual obligations to protect. For the rest of us, searches that can reach our personal correspondence, health information, and financial records are reasonably viewed as an affront to privacy and dignity and inconsistent with the values of a free society."
- goblin89 15y ago
  Not to argue with your points (business data is sensitive stuff), but another link from the article leads to this: > For maximum security make sure you are alone and close the curtains. Write on a hard surface - not on a pad of paper. After you memorize your passphrase, burn your notes, pulverize the ashes and flush them down the toilet. That is quite a paranoid's hell. =) Full-disk encryption may just provide false sense of safety, as we store lots of data in the cloud, where even strong passwords do not guarantee that nobody will get access to the data. IMO for one to be 100% sure that nothing could go wrong one should not store anything anywhere.
  - icebraining 15y ago
    Full-disk encryption may just provide false sense of safety, as we store lots of data in the cloud, where even strong passwords do not guarantee that nobody will get access to the data. You can store an encrypted file "in the cloud", though. A truecrypt volume with a keyfile should be essentially uncrackable. Of course, then you can only use the service as a dumb data storage.
fletchowns 15y ago
I think we would all be a little amazed and horrified at the actual amount of sensitive identify information is floating around on thumb drives and usb hard drives.
thibaut_barrere 15y ago
I use crypted vaults for all my customer projects. I couldn't sleep well otherwise.
- daeken 15y ago
  I use FDE and then encrypted vaults for each project. Even if my computer is lost/stolen when it's on or asleep and the FDE does nothing, I can be assured that the vast majority of the sensitive data is safe.
  - thibaut_barrere 15y ago
    I'm adding FDE too :) I use Knox for Vaults (on Mac), what do you use out of curiosity?
    - daeken 15y ago
      Knox on OS X (what I use for day job work) and Truecrypt on Windows. PGP Desktop for FDE.
    - sitkack 15y ago
      Knox is a better UI for the bultin in folder encryption on OSX?
      - thibaut_barrere 15y ago
        see http://help.agilebits.com/Knox/why_knox.html http://help.agilebits.com/Knox/why_knox.html
        sitkack 15y ago
        Cool. I already do something similar with encrypted sparseimages, I will give this a try.

tobiasbischoff 15y ago

On OSX with Lion - there is no excuse http://osxdaily.com/2011/08/10/filevault-2-benchmarks-disk-encryption-faster-mac-os-x-lion/ http://osxdaily.com/2011/08/10/filevault-2-benchmarks-disk-e...

nonane 15y ago
Have you noticed crashes and general instability on OS X Lion + Filevault 2? We've tried it on a Core2Duo Macbook Pro (early 2007) and MacBook (Mid 2010). We've seen lots of OS crashes (Macbook) and general performance issues when running XCode (Macbook Pro). We're also running virtualization software on the Macs (Parallels and VMWare) - I'm not sure if they're interacting with Filevault 2 (shouldn't be). Just wonder if anyone else has noticed this.
- benologist 15y ago
  I use it on a 2011 Air and Mini without problems, and I'm just about always in Parallels on both machines.
- maukdaddy 15y ago
  I use Lion's Filevault 2 on an early 2009 MBP and have not had any crashes or stability problems at all. FV2 on Lion is light years ahead of the broken Filevault 1 (Snow Leopard) implementation.
- tobiasbischoff 15y ago
  no i have no problems. macbook air 2010 w/ lion + file vault active - no crashes or instability. i do time machine backups on a regular basis and work with Xcode, photoshop, iWork, vmware fusion - never had any problem.
Tichy 15y ago
Does it now play well with Time Machine?
- mark_l_watson 15y ago

kia 15y ago

Microsoft BitLocker in its most secure mode is the gold standard because it protects against more attack modes than other software. Unfortunately, Microsoft has only made it available with certain versions of Microsoft Windows. Though MS says that BitLocker doesn't have back doors [1], I wonder how true this actually is... [1] http://blogs.msdn.com/b/si_team/archive/2006/03/02/542590.aspx http://blogs.msdn.com/b/si_team/archive/2006/03/02/542590.as...

sliverstorm 15y ago
Do MS developers have a track record of bald-faced lies that I'm unaware of?
- dhbanes 15y ago
  http://en.wikipedia.org/wiki/NSAKEY http://en.wikipedia.org/wiki/NSAKEY
slowpoke 15y ago
Exactly. Trusting proprietary, closed source software (in other words, a third party) for encryption is missing the point of encryption so hard, it's not even funny.
- jazzyb 15y ago
  To be fair, I trust TrueCrypt because it's "libre" and "open", but I've never looked at the source code myself. I trust that other people more knowledgable than me have taken a look at it, but if there is indeed a backdoor in it, then it will look on the surface like the most innocuous bug in the world. Don't get me wrong: I understand and appreciate your point, but I honestly don't know how most of us using TrueCrypt (e.g. me) are any better off than those who use a proprietary solution. The only difference I can see is any backdoors in TrueCrypt or PGP must be better hidden.
  - slowpoke 15y ago
    While you are basically correct, the mere ability to check the source yourself and possibly be able to find (or even fix) said bugs-which-could-or-could-not-be-cleverly-hidden-backdoors puts it leagues ahead of any proprietary solution, where there is never any way to be sure there isn't just something like a void force_decrypt(string company_master_password)[1] in there. And to be perfectly honest, I'd rather trust the FLOSS crowd who checked TrueCrypt and other more or less popular encryption tools probably hundreds, if not thousands of times than trust the development team of a company refusing to release the source of their software. [1] Yes, I am kidding, but I hope you catch my drift.

codesuela 15y ago

I got myself an SSD for Christmas and that is why I moved off full disk encryption on home computer and instead encrypt almost everything except the system. However I've turned off the page file and I'm trying to set up pre boot authentication for non system volumes. On another note, I plan to slowly switch to Ubuntu and I wonder how secure the home folder encryption is?

mike-cardwell 15y ago
There's nothing stopping you using FDE on an SSD...
- codesuela 15y ago
  FDE on a SSD negates the gained speed advantage
  - mike-cardwell 15y ago
    Does it? Even if you have a CPU with AES-NI instuctions like an Intel Core i5 or i7?
    - codesuela 15y ago
      unfortunately yes, see http://blog.siyuz.net/2010/11/17/truecrypt-7-0a-fde-on-ssd/# http://blog.siyuz.net/2010/11/17/truecrypt-7-0a-fde-on-ssd/#
      - arthurschreiber 15y ago
        I encrypted my SSD using BitLocker, and for me, the performance hit is not really noticable in my day-to-day work (programming + running a virtual machine). Your SSD will still be A LOT faster than a regular, unencrypted HDD. But YMMV.
      - polshaw 15y ago
        This case is only relevant to SSDs with a sandforce controller, however -- as (only) the sandforce controller compresses data for increased speed, which cannot be done with encrypted data.

wazoox 15y ago

None of my current computers is powerful enough for that without it being a serious hassle. And I'm pretty sure it will drain my laptop battery much faster...

thibaut_barrere 15y ago
Which OS do you use? On Mac OS X I use Knox; my 2006' MBP doesn't have any issue with that.
- wazoox 15y ago
  I'm running Linux everywhere, and Snow Leopard on my MacBook. I find the MacBook a bit slow at time (mostly because of the 2GB RAM I guess). I still use an ancient Athlon64 single core with 1GB as my main desktop, though :)
sitkack 15y ago
It looks like many people assume this to be so but haven't done the benchmarks. FDE is going to be a much smaller hit than say anti-virus software. Encryption routines have been highly optimized into the multi gigabytes per second range.
- wazoox 15y ago
  > FDE is going to be a much smaller hit than say anti-virus software. But I don't run any anti-virus, this is even one of the good reasons why I stopped using windows aeons ago. I tried LUKS with AES a few years ago, and though the performance was good it comes with a really significant hit.
RexRollman 15y ago
I have tested Windows 7 with both Bitlocker and Truecrypt, and Arch Linux with with LUKS, on my four year old Dell e520 (a 1.8ghz Core 2 Duo 6300 PC with 4GB of RAM). I didn't notice any real performance difference with FDE enabled, although I am sure a proper benchmark tool would have shown something.
15y ago

ck2 15y ago

It's sad we need encryption mostly for protection from not criminals, but our own government for even trivial data. What freaks me out most these days is how easily people fall into the belief that "oh well traveling is not a right so you have to give up rights when you fly or drive anywhere". No, if you are a citizen of the United States and unless you are actually crossing a border, you should have the unqualified protection against unreasonable searches, especially without warrants. I also don't accept the "well it's worse in other countries, be happy you are not there" argument. This country is not even 250 years old. The laws we made are pretty fundamental and not old at all. It's not some kind of game where they should be allowed to dance around the edges to break them.

flipbrad 15y ago
To be honest, I don't see why national borders are so strongly part of the equation. I suppose that depends on your worldview. I live within the Schengen Area, and to me it seem patently obvious that most 'bad things' in the world are hardly affected by national borders. They're typically supra-national (climate change, credit crunch, cracking, etc) or intra-national (most crime, etc. I don't mean to argue for more checks / security measures, overall, but why do you want them to be focused at the border?
- icebraining 15y ago
  Drug trafficking and illegal immigration?
  - Willwhatley 15y ago
    Human trafficking is the new drugs. Apparently it's enormously more profitable to import sex workers and keep them in a kind of narcotic/whatever assisted slavery, because of the reuse of the person vs. the consuming nature of the drug.
    - flipbrad 15y ago
      We're getting way off topic but I'd be interested to see a source for that claim. I imagine that the costs associated with a prostitute (food, shelter) would be significantly higher than those associated with a stock of inert crystalline powder, pills, or resin. Even if nominally borne by the prostitute, those greater costs still reduce the profitability of the overall enterprise.

code4pizza 15y ago

I wonder if there would be significant environmental implications if everyone switched to full disk encryption... Does this impose a significant processor load and does that translate to greater power consumption?

justanotheratom 15y ago
I wouldn't worry too much about it. There is a fixed CPU overhead, but negligible. http://www.tomshardware.com/reviews/bitlocker-truecrypt-encryption,2587-9.html http://www.tomshardware.com/reviews/bitlocker-truecrypt-encr...
sitkack 15y ago
An idling CPU and a slightly loaded CPU use about the same amount of energy. I think my Q6600 quad used 190W @ idle and running full tilt cpu (ray tracing) it was using 220W. For FDE it depends on how much IO you are doing. I doubt it will make even a 0.01 difference in your daily power consumption.
- mikeash 15y ago
  I don't think so. On my laptop, fully loading the CPU takes it from silent to screaming fans in about two minutes. That's clearly a big change in heat production and therefore power consumption.
  - sitkack 15y ago
    You should use a kill-a-watt and measure it. Probably less than you think. Laptops already on the edge of their thermal envelopes, anything above their low steady state (browsing, listening to music) will cause the fans to spin.
    - mikeash 15y ago
      The battery time remaining will also drop by a factor of 4 or more. This is large enough that I don't think a more precise instrument is needed to determine that the effect is significant.

jrgifford 15y ago

Unfortunately, the amount of time I spend running/breaking the development version of Ubuntu prohibits full disk encryption, but I do have /home encrypted. Is that "good enough"?

morsch 15y ago
That's what I intend to do the next opportunity I get. Your swap space could still leak confidential information, though.
- jrgifford 15y ago
  I'm willing to risk that since I rarely use any of my swap.
  - slug 15y ago
    You can and should encrypt your partition, since your home key might end up there. https://help.ubuntu.com/community/EncryptedFilesystems https://help.ubuntu.com/community/EncryptedFilesystems If you want hibernate to work you can use uswsusp for example: https://we.riseup.net/debian/encrypted-swap https://we.riseup.net/debian/encrypted-swap Sleep always works, but as mentioned above, your key will be in memory...
    - jrgifford 15y ago
      Interesting.... I think i'll stick with user directory encryption, but thanks for those links.
      - slug 15y ago
        Well, I use /home with luks on some machines and user directory (encfs) on others, but have all of them with swap encrypted or no swap partition at all. Since the keys/other private info might leak there, you are not doing it right, unless you have sysctl swappness level set to 0. Not only that, /tmp and other temporary directories might also be another leaky place...

SickAnimations 15y ago

My system triple boots into OS X, Windows and Ubuntu. I have a home partition, formatted in HFS+. What would be the best strategy for me to use? Should I just encrypt the home volume using something cross-platform like TrueCrypt, or is it practical (an maintainable) to do full-disk encryption in such an environment? My home partition has very sensitive data and I've been putting off creating a TrueCrypt container for this data.

nonane 15y ago
This is probably not answering your question but a possible solution is to switch to using OSX 100% of the time and then use Parallels/VMWare/VirtualBox to virtualize Windows and Ubuntu. It's much more practical than having to worry about partitions / boot volumes and general sharing problems. This way you can even encrypt your entire OS X volume and not use encryption on the VMs.
m3koval 15y ago
I'm also dual booting OS X and Ubuntu with a shared home partition formatted as HFS+. Getting the encryption to work nicely in Linux sounded pretty easy, but I couldn't figure out how to do it in OS X. My current solution is to store anything particularly sensitive in a TrueCrypt file...obviously not the best solution. Out of personal interest: Did you get Linux to mount the HFS+ partition with R/W access with journaling enabled? I am also curious if you make any progress with encrypting the entire partition.

Jach 15y ago

If you go full disk encryption with TrueCrypt, make sure you look into their Hidden OS feature as well. A judge may be able to order you to give up the decryption key to the OS when accessing the drive prompts for one (last I checked the precedent is still somewhat shaky), because while they can't know what's being encrypted they can infer something readable is. They can't prove the existence of a Hidden OS, though, so your 'real' encrypted area is just noise and can't be legally proved anything else so a second key can't be demanded.

hetman 15y ago
Might look odd if none of the files on the decoy have been modified in the last 6 months - logging in to do this regularly and in a believably meaningful way seems like a burden. The good news is unless you're an international crime lord, it seems unlikely there will be anyone on hand in the court to make this kind of leap (not a lawyer so that guess could be way off though).
- jpdoctor 15y ago
  An automated update of the decoy would be a good addition to such software.
  - fl3tch 15y ago
    Not sure exactly how this would be implemented, but it sounds like a bad idea, since they would just wait for your automated updater to decrypt the decoy. Even if it was in some limited fashion, the encryption key would be in RAM, so it would be as vulnerable as any running system. (BTW, if you're worried about a state-level adversary, that means you should always turn off your computer when not using it, and wait a few minutes before physically leaving it to prevent a cold boot attack)
    - esrauch 15y ago
      Well, the point of the decoy i that you don't care if they can access it isn't it?

brador 15y ago

I just use two RAIDed NAS boxes, one as a long term, large file media/data store and another for small files on SSD RAID. All my comps are now dumb terminals, booting an OS and software. Works well and was surprisingly cheap for what is essentially a complete, hassle free system.

josscrowcroft 15y ago

Enlightening (and scary) stuff. Encryption is great but won't save you if they ask for your password (honestly, I'd prefer to give them the password and circumvent using online storage.) With that in mind - what advice would all you security buffs have on the best way to back up your hard drive to an online disk? Specifically using a basic hosting account as opposed to SAAS or cloud service?

po 15y ago
I actually trust tarsnap more than setting up a host and having to maintain it: http://www.tarsnap.com/ http://www.tarsnap.com/
- josscrowcroft 15y ago
  Looks very interesting, as services go. For this kind of thing, I'm strangely less inclined to trust a slick-looking, well-designed and heavily-marketed backup "solution".. If I do fork out for a service, I would probably rather go with the kind of company that has as their tagline: "Online backups for the truly paranoid", like them. Pricing's not a killer either.
  - po 15y ago
    This service is run by a long time hacker news user and security researcher cperciva. Read his stuff: http://news.ycombinator.com/user?id=cperciva http://news.ycombinator.com/user?id=cperciva http://www.daemonology.net/blog/ http://www.daemonology.net/blog/
  - merijnv 15y ago
    The reason I trust (to the extend I trust anything on this planet) Tarsnap is that Colin Percival (the creator) is a cryptographer and the FreeBSD security officer. Leading to me have a higher confidence in him than most of the other "secure" backup services I have seen.
    - josscrowcroft 15y ago

cafebabe 15y ago

Next year's resolution: Getting out of holding / prison without compromising the passphrase to your fully encrypted disk.

justatdotin 15y ago

do most people really have private information on their computer? I don't think I do ...

baq 15y ago
depends what you consider private. for me, everything is private as long as i don't put it online consciously. yes, even that photo of me sitting on a chair.

casca 15y ago

It's nice that computers are now powerful enough that full disk encryption is almost performance-neutral. But realistically, if they want your data then they can get it. Spear phishing works very well and if not, there's always indefinite detention. Technology is only a small part of the solution to warrantless border searches.

mike-cardwell 15y ago
What encryption gives you is choice. If you don't use it, then you never have the choice of whether or not to give up data. The choice is taken for you. If you use encryption there are many attackers that you will be able to prevent being able to access the data.

DanielBMarkham 15y ago

I'm not an expert on security, but I do know a bit about human nature. I'd suggest a 2-level encryption scheme. Perhaps FDE and a BIOS password as level 1, and then a futher encrypted area of your HD as level 2. Why? Because this allows you to appear to be cooperating with any request to look at your computer. Simply type in the level 1 stuff and demonstrate the system booting up. I bet 9 times out of 10 whoever is checking you over will stop right there: it looks a lot like compliance. If they keep pushing for total access to your data simply say "no" Whereas if you say "no" to begin with, you're likely to attract more attention than if it appears you have nothing to hide. In many cases people are working jobs where they only have so much time to check things -- unless there appears to a be a person with a problem, in which case they can take all day with you. So help them out. Give them something to ask you for that you can produce. Then everybody can move along and it's not a problem for anybody.

nohat 15y ago
Truecrypt has a hidden OS option. It does sound like some work, however.
tocomment 15y ago
Once you boot up and log in couldn't they see your whole system.
- culturestate 15y ago
  Not if your secondary partition isn't mounted automatically. It's not a stretch to assume that customs agents (or whomever) aren't going to look for unmounted partitions when the computer is booting and running normally.

trotsky 15y ago

The feds and other serious folks are pretty careful these days not to turn off anything until they've had forensics evaluate the situation. And not just because of FDE, memory analysis very frequently yields the best evidence due to it's timely and overlooked nature. Since most encryption systems retain their keys during lock and sleep, unless you usually leave your system powered off I wouldn't count on being afforded much privacy if you're interesting enough to bother. That said I still use it on both of mine and definitely suggest it, it's a very small performance penalty for what will be a godsend if your laptop turns up lost or stolen. https://code.google.com/p/cryptsetup/ https://code.google.com/p/cryptsetup/ It's an excellent precaution against the much more mundane and common threats like loss or theft though

fl3tch 15y ago
If you're worried about a state-level adversary, then yes, you should always turn off your computer when not using it. They could still be spying on you and wait until you turn it on to kick down the door. There are people who have thought about these things, too. One suggestion is a dead man's trap, like a pad that you sit on, so if the door gets kicked down (or they snipe you from outside the window), as soon as you stand up (or fall off the stool) it scrambles RAM and shuts down the system. That's a super high level of paranoia, but still makes encryption useful.
- epochwolf 15y ago
  You could just hold down the power button on your computer for 4 seconds and require a password to boot the system.
  - pyre 15y ago
    That depends on how quickly they can get guns pointed at you once the door is kicked in.
    - epochwolf 15y ago
      Okay, then you can set up your system to do a force shutdown if the power button is hit. If you're on a desktop, have a power strip near your foot so you can kick the toggle switch if the door comes down. (Or have a big red kill switch wired into the power supply on the front of the case.) The latter option probably won't earn you any favors with the judge or the jury.

finnw 15y ago

I am not convinced by one of the quiz answers: > Our calculations confirm that a relatively short series of truly randomly chosen English dictionary words is secure; many people find these somewhat more memorable. Above we used "In the jungle! The mighty Jungle, the lion sleeps tonight!" The important thing is to choose enough words and to choose them in a random un-guessable way, such as by changing the spacing, punctuation, spelling, or capitalization. The problem with this example is that the 10 words are not chosen independently. Type "in the j" into a google search box and the whole phrase will appear in the drop-down box. So the entropy for the choice of that phrase is about lg2(37^8) or about 42 bits. So an approximation of the total entropy is: Choice of source phrase = lg2(37^8) ~= 41.7 bits Choose one of the 10 suggestions from the drop-down box = lg2(10) ~= 3.3 bits Permutation of words = lg2(10! / 2! / 3!) ~= 18.2 bits Spacing (assume each word may independently be precedeed by a space with probability 0.5) =10 bits Punctuation (each word may be independently followed by '!') = 10 bits Capitalization: independently choose one of {lowercase, camelcase, uppercase) for each word = lg2(3^10) ~= 15.8 bits Total so far: 98 bits. Now consider the third option: a mixture of 16 independently-chosen letters, numbers and symbols. Assume most ASCII characters are available (lets eliminate single quote, backslash and $ which cause problems for some web apps) and we have lg2(92^16) ~= 104.4 bits, which wins.

dlytle 15y ago
The point is that "In the jungle" etc can actually be reliably remembered by a large portion of the population, whereas 16 independently chosen letters/numbers/symbols usually can not. Humans are great at remembering phrases, quotes, etc. Think about how widespread referential humor is, where the joke is just a reference to/quote from another work. That's something the brain is great at. Random or semi-random jumbles of letters? Not so much.
- Cyranix 15y ago
  In illustrated fashion: http://xkcd.com/936/ http://xkcd.com/936/

phillmv 15y ago

What's the performance penalty like? That's pretty much the only thing holding me back.

tcas 15y ago
Pretty minimal. If you have TrueCrypt installed you can run a benchmarks of various algorithms. It's especially fast if you have a modern processor with AES-NI (hardware AES instructions) -- I get around 1GB/s Encrypt/Decrypt using AES on a Core i5.

Havoc 15y ago

I'm concerned about privacy too but none of the worrisome areas would be improved by FDE. Facebook/Google, tracking, keyloggers etc is where the main problem lies.

quinndupont 15y ago

Does anyone have any thoughts on Apple's File Vault? I assume the crypto is perfectly fine, but I worry about bugs destroying my data.

quinndupont 15y ago
Apparently FileVault has been much improved in OS X Lion: http://www.maclife.com/article/howtos/how_use_filevault_and_time_machine http://www.maclife.com/article/howtos/how_use_filevault_and_...

samstave 15y ago

What about on my mobile? I am not aware (as I havent looked) of any encryption available to the data on my iPhone, or MyTouch 4G. Further, I use Gmail - I have zero expectation of privacy from google. I also store all my important docs for work and personal on DropBox. What will I gain from encrypting my laptop? aside from it being stolen/lost - I dont see any added security/benefit from doing this. I am not trying to be obtuse - but can one explain to me why I would want to do this, other than expressing my tech savvy?

tjoff 15y ago
Android ICS and Honeycomb allows for your data to be encrypted. Don't use gmail and don't use dropbox for unencrypted files ;) But seriously, the risk of your laptop being stolen or lost is a huge incentive for encrypting it. I feel much better knowing that the worst that could happen with my laptop is that i loose it (stolen/lost/dropped). I wouldn't wan't to be uncertain whether anyone had access to my personal files if it got lost and the data I have on it is more valuable than the hardware (and I'm still a student...). For anyone that is tech savvy I see no reason not to do FDE. Okay, two exceptions. Loosing TRIM support on SSD-drives and travelling to/from countries that feel they have the right to inspect the content of my laptop and that might frown upon the fact that it is encrypted.
culturestate 15y ago
iPhone data is encrypted by default - remote wipe works by destroying the key. Unfortunately, the key is obviously only protected by a user's passcode, if they've even set one. The 4-digit pin codes have been shown to be broken, but I've not seen (maybe I missed it?) evidence of those with alphanumeric passcodes being compromised.
- rdl 15y ago
  The issue is that I can conduct an unlimited-attempts brute force attack against the passcode. I can do about 10 per second on an iPhone 4S, but I do need access to the machine, unless I'm willing to crack open the iPhone and do a destructive hardware attack. At 10 per second, I feel ok with an 8-10 character numeric passphrase, or a 7-8 character lowercase-only passcode. I just wish the iPhone had some intelligence about adaptive locking -- lock faster when it's outside my home/car, don't go from unlocked to locked very fast, if at all, if docked in secure places inches from a 9mm. Or pairing with an RF device attached to me, like the Blackberry CAC reader.

paulhauggis 15y ago

This is all good, until you get any kind of disk corruption. Good luck getting any of your data back.

outworlder 15y ago
That's why you should have up-to-date backups.
- paulhauggis 15y ago
  but then couldn't people still get to your unencrypted data (through your backups)?
  - culturestate 15y ago
    If you're doing FDE, you should be encrypting your backups as well. It can be relatively trivial, depending on your backup setup.
    - jodrellblank 15y ago
      This is all good, until you get any kind of disk corruption. Good luck getting any of your data back.
      - culturestate 15y ago
        If my encrypted disk becomes corrupted and then corrupts my unencrypted backup, what's the difference?
        jodrellblank 15y ago
        A good backup, e.g. Time machine, lets you restore feom before the corruption. A backup on an encrypted disk risks the entire backup volume being corrupted and unusable in one go, thus making it a very brittle backup. I'm assuming that a corrupted encrypted file is totally unusable here, and now that I think more about it I'm not sure - encryption with chained blocks would mean errors have a larger affect than just at the error site, wouldn't it?

nohat 15y ago

One thing that worries me is how difficult it makes it if you get some data corruption. For example, I had a hardrive that had full disk encryption start to fail, and found pulling the data off much more difficult because I had to decrypt the whole lvm to get any access. I'm actually not confident how exactly corruption maps from cyphertext to plaintext in various modern crypto systems. I would guess that you would get out gibberish though.

spindritf 15y ago
I would rather back my data up than hope to retrieve it from a corrupted fs or, worse, a failing disk.

pasbesoin 15y ago

Can anyone comment on the speed/performance of TrueCrypt, EncFS, and similar on older systems, e.g. a 5 - 7 year old laptop? I'm considering carrying a "sacrificial" machine in case it is, um, "indefinitely detained", but I'm uncertain what kind of a performance hit full disk (or partition -- though I'm inclined to encrypt the entire disk) encryption will incur. (I currently have Core Duo and P4 candidates for the job.)

tjoff 15y ago
Truecrypt has a simple benchmark that you can try (and I think it has a portable installation option so you don't even have to install it on the system to try it out). My core duo 1.6 GHz laptop gets about 60 MB/s of AES encryption/decryption speeds on battery (which I think reduces the clock to 1 GHz). I consider the impact negligible. However if you have an SSD in your system and do full-disk-encryption you will loose potential TRIM-support which can have a significant performance penalty depending on drive.
- pasbesoin 15y ago
  Thank you for the response. These are both "spinning plates" machines. Part of what would keep their loss a minor financial hit. I wonder whether the dual cores help significantly. (As I'm more inclined to make the P4 the sacrifice.) However, if your observation is that the perceived impact is "negligible", this encourages me that it will be acceptable, if more significant, on the P4. I hadn't noticed the benchmark utility you describe. I'll have a look for/at it. Thanks!

bengl3rt 15y ago

Unfortunately, full-disk encryption absolutely kills SSD performance because it makes the data look random (i.e. incompressible). It will wear out the SSD much faster than using it without would, because the hardware compression unit in the controller can sometimes achieve 8:1, and therefore have to rewrite only 1/8th of the NAND cells that it otherwise would.

gojomo 15y ago
I think you're right on the effect but wrong on the implied grave magnitudes "absolutely kills" and "much faster", because: • not all SSDs even have hardware compression • modern workloads have less highly compressible data than in the past: large-media formats include their own compression, and bulk data processing often does its own application-level compress/decompress on store/load I'd be interested to see any benchmarks that quantify the speed/lifetime hit that whole-disk encryption might cause for SSDs, but my hunch is that the effect would be slight in normal scenarios.
- culturestate 15y ago
  Anand benchmarked FileVault(1) and his conclusion was "Overall the hit on pure I/O performance is in the 20 - 30% range. It's noticeable but not big enough to outweigh the benefits of full disk encryption." 1. http://www.anandtech.com/show/4485/back-to-the-mac-os-x-107-lion-review/18 http://www.anandtech.com/show/4485/back-to-the-mac-os-x-107-...
  - kgtm 15y ago
    Yes, but that result is most likely on a Sandforce-powered SSD, which sports different transfer speeds based on the payload (compressible/incompressible). Like the GP notes, this is not a problem with SSDs in general.
    - culturestate 15y ago
      That benchmark is with a stock Apple SSD, which IIRC are not Sandforce-based. To be clear, I'm actually in agreement with Anand and OP - the benefits of FDE far outweigh the consequential I/O hit.

dicroce 15y ago

I did this over a year ago and am very happy. I use TrueCrypt. I have not noticed any slow downs (even for gaming)... That said, you should probably not do this if your drives are failing (or you tend to suffer a lot of disk failures).

rogerbinns 15y ago

So how do you encrypt a home server? Any device that has to be bootable without human intervention will have to store the encryption keys on the device somewhere making the encryption merely obfuscation. It is possible for "swap" RAM to be encrypted on Linux and it could generate a random per boot key, also being a form of obfuscation. https://lkml.org/lkml/2011/12/28/69 https://lkml.org/lkml/2011/12/28/69

deleted 15y ago

[deleted]

bumbledraven 15y ago

It's great to see the EFF recommending http://diceware.com http://diceware.com for secure passphrase generation.