20 ms·

Brian from Backblaze here. All the data is encrypted and spread throughout our datacenters. So we fetch each file and decrypt it (with the password you provid

Brian from Backblaze here. All the data is encrypted and spread throughout our datacenters. So we fetch each file and decrypt it (with the password you provided when kicking off the restore). If this is less than 1 GByte it is instantaneous. But if it is a TByte of data, it takes a few hours to decrypt and add to the ZIP file.

monochromatic 9y ago
That makes sense, thanks for the response. (4 days and counting still seems excessive though.)
- brianwski 9y ago
  Definitely seems excessive. We'll look into it. There are some things that can affect it. We have a "pool" of restore servers that do this task. The oldest ones in the pool are 9 year old computers with slow hard drives. The newest restore servers are built on SSDs and are blazingly fast and have newer processors. So based on which restore server was assigned the task, plus other things like the size of each file can speed or slow the restore. We are in the middle of a project to speed up all restores. Hilariously we figured out that simply by decommissioning the oldest, saddest restore servers the restores averaged FASTER restore times.
  - BillinghamJ 9y ago
    Presumably you mean faster than the non-hardware solution you were working on?
explainplease 9y ago
This is confusing and concerning to me as a potential customer. Having used CrashPlan and other proprietary and FOSS backup software, I don't understand this description of how restoration works with Backblaze. 1. Why is the data being decrypted server-side instead of client-side? The server should be sending the encrypted data to the client, and the password should never leave the client machine. 2. Why are zip files being created? The client software should be receiving the data and writing the files directly to the selected restore directory. e.g. this is how restore works with CrashPlan, and it only takes a few seconds to begin the process. Files are written directly to the selected output directory.
- brianwski 9y ago
  I'll answer these in reverse order: > 2. Why are zip files being created? We actually offer two forms of restore: A) Zip File Download, and B) External USB Hard Drive FedEx'ed to your home. In the case of the Zip file download, we chose the format of zip because both Mac and PC (the most common desktops) natively understand it with no additional software needed. In other words, if you just lost your computer, go to ANY COMPUTER ANYWHERE and you can fetch your files with a web browser. Zip preserves the file hierarchy and the last modified time, so it's "pretty good". In the case of the USB Hard Drive there is no zip file, we can correctly place each file with all the correct timestamps in the correct heirarchy on the USB Hard Drive (which is actually an encrypted hard drive) and then FedEx the hard drive to you anywhere in the world in a day or two. > 1. Why is the data being decrypted server-side instead of client-side? Short Answer: Ease of use. Longer Answer: To clarify, Backblaze produces four different products/modes for different customers with different needs and requirements. We want customers to choose what is appropriate for them. One size does not fit all: 1) Online Backup ($5/month) where every file is encrypted on your laptop BEFORE being sent to Backblaze and your backup is secured by your username/password - where you can recover your password if you have access to your email account. (We support two-factor auth which provides an additional optional layer of protection.) 2) Online Backup ($5/month) where every file is encrypted on your laptop BEFORE being sent to Backblaze and your backup is secured by your username/password AND your private encryption key is secured by a "passphrase" that is not recoverable in any way, shape, or form. (Two-factor auth is also optional here.) 3) B2 Object storage (half of 1 cent/GByte/month) where you store your file completely unencrypted, and this can be "private" (only accessible by username/password) or "totally public accessible by knowing the URL". A good application of this is serving up a web page to the public - you really WANT people to see all the contents! 4) B2 Object storage (half of 1 cent/GByte/month) where Backblaze has zero knowledge. You cannot browse your file hierarchy because Backblaze doesn't know your filenames. You cannot preview your images. You cannot recover your passwords. There is no other option other than downloading the encrypted blobs and applying whatever decryption algorithm you decided on (we have no ability to know what that is). Ok, so I think some (many?) people in the security field think that Backblaze should ONLY offer mode #4 (and maybe #3 to serve up public websites). I happen to disagree and I personally feel that products #1 and #2 are useful and appropriate for some customers. But everybody is welcome to their opinion and we want to be completely open as to what exactly is occurring and what we are offering as a service. Personally I think #2 is an excellent trade off of security vs convenience. Your data is as impervious to attack as a zero knowledge system in #4 for years upon years. Then one day your laptop is stolen or crashes and you want your files back. You want all 4 TBytes back - so you order one of our free (encrypted) USB hard drives to be FedEx'ed to your home with all your data. To kick this process off FOR THE FIRST TIME EVER you tell us your passphrase (up until this very moment it really has been zero knowledge). At this moment you are opening a window of SLIGHTLY lowered security that slams shut after a few hours. For those few hours of preparing your 4 TByte restore, if an undetected hacker had compromised the one restore server in the Backblaze data center that your job was on, that hacker could possibly get access to your files. But then the reduced security window slams shut, we NEVER write your passphrase to any disk so it has now vaporized and we do not remember it, and if a hacker hacks into our system the following day you are STILL completely impervious. But again, as long as you fully understand the implications of #3 I am COMPLETELY supportive if you instead choose #4 which is our "Zero Knowledge" offering.

monochromatic 9y ago

That makes sense, thanks for the response. (4 days and counting still seems excessive though.)

brianwski 9y ago
Definitely seems excessive. We'll look into it. There are some things that can affect it. We have a "pool" of restore servers that do this task. The oldest ones in the pool are 9 year old computers with slow hard drives. The newest restore servers are built on SSDs and are blazingly fast and have newer processors. So based on which restore server was assigned the task, plus other things like the size of each file can speed or slow the restore. We are in the middle of a project to speed up all restores. Hilariously we figured out that simply by decommissioning the oldest, saddest restore servers the restores averaged FASTER restore times.
- BillinghamJ 9y ago
  Presumably you mean faster than the non-hardware solution you were working on?

explainplease 9y ago

This is confusing and concerning to me as a potential customer. Having used CrashPlan and other proprietary and FOSS backup software, I don't understand this description of how restoration works with Backblaze. 1. Why is the data being decrypted server-side instead of client-side? The server should be sending the encrypted data to the client, and the password should never leave the client machine. 2. Why are zip files being created? The client software should be receiving the data and writing the files directly to the selected restore directory. e.g. this is how restore works with CrashPlan, and it only takes a few seconds to begin the process. Files are written directly to the selected output directory.

brianwski 9y ago
I'll answer these in reverse order: > 2. Why are zip files being created? We actually offer two forms of restore: A) Zip File Download, and B) External USB Hard Drive FedEx'ed to your home. In the case of the Zip file download, we chose the format of zip because both Mac and PC (the most common desktops) natively understand it with no additional software needed. In other words, if you just lost your computer, go to ANY COMPUTER ANYWHERE and you can fetch your files with a web browser. Zip preserves the file hierarchy and the last modified time, so it's "pretty good". In the case of the USB Hard Drive there is no zip file, we can correctly place each file with all the correct timestamps in the correct heirarchy on the USB Hard Drive (which is actually an encrypted hard drive) and then FedEx the hard drive to you anywhere in the world in a day or two. > 1. Why is the data being decrypted server-side instead of client-side? Short Answer: Ease of use. Longer Answer: To clarify, Backblaze produces four different products/modes for different customers with different needs and requirements. We want customers to choose what is appropriate for them. One size does not fit all: 1) Online Backup ($5/month) where every file is encrypted on your laptop BEFORE being sent to Backblaze and your backup is secured by your username/password - where you can recover your password if you have access to your email account. (We support two-factor auth which provides an additional optional layer of protection.) 2) Online Backup ($5/month) where every file is encrypted on your laptop BEFORE being sent to Backblaze and your backup is secured by your username/password AND your private encryption key is secured by a "passphrase" that is not recoverable in any way, shape, or form. (Two-factor auth is also optional here.) 3) B2 Object storage (half of 1 cent/GByte/month) where you store your file completely unencrypted, and this can be "private" (only accessible by username/password) or "totally public accessible by knowing the URL". A good application of this is serving up a web page to the public - you really WANT people to see all the contents! 4) B2 Object storage (half of 1 cent/GByte/month) where Backblaze has zero knowledge. You cannot browse your file hierarchy because Backblaze doesn't know your filenames. You cannot preview your images. You cannot recover your passwords. There is no other option other than downloading the encrypted blobs and applying whatever decryption algorithm you decided on (we have no ability to know what that is). Ok, so I think some (many?) people in the security field think that Backblaze should ONLY offer mode #4 (and maybe #3 to serve up public websites). I happen to disagree and I personally feel that products #1 and #2 are useful and appropriate for some customers. But everybody is welcome to their opinion and we want to be completely open as to what exactly is occurring and what we are offering as a service. Personally I think #2 is an excellent trade off of security vs convenience. Your data is as impervious to attack as a zero knowledge system in #4 for years upon years. Then one day your laptop is stolen or crashes and you want your files back. You want all 4 TBytes back - so you order one of our free (encrypted) USB hard drives to be FedEx'ed to your home with all your data. To kick this process off FOR THE FIRST TIME EVER you tell us your passphrase (up until this very moment it really has been zero knowledge). At this moment you are opening a window of SLIGHTLY lowered security that slams shut after a few hours. For those few hours of preparing your 4 TByte restore, if an undetected hacker had compromised the one restore server in the Backblaze data center that your job was on, that hacker could possibly get access to your files. But then the reduced security window slams shut, we NEVER write your passphrase to any disk so it has now vaporized and we do not remember it, and if a hacker hacks into our system the following day you are STILL completely impervious. But again, as long as you fully understand the implications of #3 I am COMPLETELY supportive if you instead choose #4 which is our "Zero Knowledge" offering.