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Curious why... Your security should never depend upon security of your source code. If you're doing things correctly, then the source code doesn't change anyth

by selykg 7y ago

Curious why... Your security should never depend upon security of your source code. If you're doing things correctly, then the source code doesn't change anything about the security of the data that is encrypted. Perhaps you mean that he chose to use 40-bit keys instead of 256-bit keys in the free version? I mean, I guess. But that's just a matter of better understanding the details. It sounds like he outlined this clearly and anyone looking for more security knew to pay for the product to get the 256-bit keys.

stevep98 7y ago
At that time, if you made software available for export (and that included making a version freely downloadable), it was limited by law to 40 bits.
- hinkley 7y ago
  The practice of looking up algorithms by name dates back to that same time. The phrasing of the law, since they were treated as munitions, was that you couldn't even export something that was designed to have crypto bolted on. So you made it so anything could be bolted on and some of them just happened to be crypto. The legacy being things like the blacklist/whitelist discussion we had the other day about case sensitivity in crypto algorithms. We still look up algorithms by string name (instead of enum or some other mechanism) decades later.
  - mratsim 7y ago
    But books had exemptions and you could export crypto as long as it was printed on a book
rcoveson 7y ago
> Your security should never depend upon security of your source code. For sure. I don't think it's about that, though. Even if the application in question were open source, if the project lead is willing to cooperate in any way their government asks, they could probable ensure the existence of a back door. For this reason, where possible, I would prefer to use encryption software written by people who are principled to a fault (or who at least do a good job acting as if they were). Let's imagine Linus Torvalds or Greg Kroah-Hartman in this same situation. Linux source is available, so let's say they were asked to ensure that a certain patch to a cryptographic API was not accepted before a certain window. Maybe the crypto API maintainers were on the call as well saying that they were on board with the plan (apologies to those people, I don't know you and mean no offense). I like to think that they would: 1. Turn down the NSA. 2. Attempt to get the word out about what they had been asked. 3. Find new crypto maintainers. And yes, it's entirely possible that this is not at all how it would go down. Maybe they would be very cooperative. I don't know any of these people personally. But what I do know is that they have not, as of yet, made a blog post about that time when the NSA did ask them to betray an unspecified user and how they did everything they asked without resistance. I don't think I'm being idealistic here. Software and encryption are global endeavors. People who blindly believe that the enemies of their state are also their enemies, or even that obedience to local laws is a moral imperative, should not write crypto software. Or at least, I hope they make their beliefs known like this guy did so that I can avoid their software.
- meowface 7y ago
  I'm pretty sure if the NSA asked him to add a backdoor, he wouldn't do it. (They already asked if he had an existing one, and he clearly realized how bad that would be if there was.)
  - rcoveson 7y ago
    That may well be true. But still, this story influences my _guess at the likelihood_ that this author would do so in the direction of "more likely." Likelihood that the authors/owners of software are willing to cooperate, and capable of cooperating, with adversaries is an important metric for comparing options. Very high profile open source maintainers are less capable, due to the oversight of the community. Anarchist- or security-absolutist type personalities are less likely. The author and his project don't fit either bill. I'm not arguing that this is the only metric that matters when considering one's options. But it does matter.
  - rckoepke 7y ago
    My understanding is that he may not have a choice. With a combination of an NSL and the all-writs-act, the US government can likely compel any non-FAANG domestic entity to do nearly anything short of murder.
- selykg 7y ago
  Being willing to provide source code is entirely different than inserting a backdoor or purposefully holding back security updates. One should have zero impact, as I said, modern crypto algorithms do not depend on keeping the algorithm secret to maintain security. Implementation can absolutely be full of bugs that are incorrectly using crypto primitives though. The other has a direct impact on security. I don't think one blurs the line to the other, they're fundamentally different things. If anything, this is further proof that you need to use crypto properly because it literally means someone with code in hands won't have any advantages in attempting to break that encryption. To me anyway, someone willing to give source code to the NSA doesn't imply they'd be willing to do nefarious things. There's nothing inherently nefarious about giving the NSA source code. That said, I can understand being skeptical, but people love to talk about how open source is more secure because it has eyeballs on it. But now we try to pull the "it's not secure because the source was given to the NSA" It can't be both ways.

by selykg 7y ago

stevep98 7y ago

At that time, if you made software available for export (and that included making a version freely downloadable), it was limited by law to 40 bits.

hinkley 7y ago
The practice of looking up algorithms by name dates back to that same time. The phrasing of the law, since they were treated as munitions, was that you couldn't even export something that was designed to have crypto bolted on. So you made it so anything could be bolted on and some of them just happened to be crypto. The legacy being things like the blacklist/whitelist discussion we had the other day about case sensitivity in crypto algorithms. We still look up algorithms by string name (instead of enum or some other mechanism) decades later.
- mratsim 7y ago
  But books had exemptions and you could export crypto as long as it was printed on a book

rcoveson 7y ago

> Your security should never depend upon security of your source code. For sure. I don't think it's about that, though. Even if the application in question were open source, if the project lead is willing to cooperate in any way their government asks, they could probable ensure the existence of a back door. For this reason, where possible, I would prefer to use encryption software written by people who are principled to a fault (or who at least do a good job acting as if they were). Let's imagine Linus Torvalds or Greg Kroah-Hartman in this same situation. Linux source is available, so let's say they were asked to ensure that a certain patch to a cryptographic API was not accepted before a certain window. Maybe the crypto API maintainers were on the call as well saying that they were on board with the plan (apologies to those people, I don't know you and mean no offense). I like to think that they would: 1. Turn down the NSA. 2. Attempt to get the word out about what they had been asked. 3. Find new crypto maintainers. And yes, it's entirely possible that this is not at all how it would go down. Maybe they would be very cooperative. I don't know any of these people personally. But what I do know is that they have not, as of yet, made a blog post about that time when the NSA did ask them to betray an unspecified user and how they did everything they asked without resistance. I don't think I'm being idealistic here. Software and encryption are global endeavors. People who blindly believe that the enemies of their state are also their enemies, or even that obedience to local laws is a moral imperative, should not write crypto software. Or at least, I hope they make their beliefs known like this guy did so that I can avoid their software.

meowface 7y ago
I'm pretty sure if the NSA asked him to add a backdoor, he wouldn't do it. (They already asked if he had an existing one, and he clearly realized how bad that would be if there was.)
- rcoveson 7y ago
  That may well be true. But still, this story influences my _guess at the likelihood_ that this author would do so in the direction of "more likely." Likelihood that the authors/owners of software are willing to cooperate, and capable of cooperating, with adversaries is an important metric for comparing options. Very high profile open source maintainers are less capable, due to the oversight of the community. Anarchist- or security-absolutist type personalities are less likely. The author and his project don't fit either bill. I'm not arguing that this is the only metric that matters when considering one's options. But it does matter.
- rckoepke 7y ago
  My understanding is that he may not have a choice. With a combination of an NSL and the all-writs-act, the US government can likely compel any non-FAANG domestic entity to do nearly anything short of murder.
selykg 7y ago
Being willing to provide source code is entirely different than inserting a backdoor or purposefully holding back security updates. One should have zero impact, as I said, modern crypto algorithms do not depend on keeping the algorithm secret to maintain security. Implementation can absolutely be full of bugs that are incorrectly using crypto primitives though. The other has a direct impact on security. I don't think one blurs the line to the other, they're fundamentally different things. If anything, this is further proof that you need to use crypto properly because it literally means someone with code in hands won't have any advantages in attempting to break that encryption. To me anyway, someone willing to give source code to the NSA doesn't imply they'd be willing to do nefarious things. There's nothing inherently nefarious about giving the NSA source code. That said, I can understand being skeptical, but people love to talk about how open source is more secure because it has eyeballs on it. But now we try to pull the "it's not secure because the source was given to the NSA" It can't be both ways.