Encryption Question

[bmanice]

If I were to encrypt a file with 7zip using AES-256, will it be as strong as encrypting the same file with TrueCrypt AES-256?

[Sparda]

Providing that 7zip's implementation is correct, yes.

[Jason Cooper]

The quick theoretical answer is yes, they would be equal strength as they are the same cipher.

In practice it would depend on the coding of the encryption routines and if there was any mistakes in either that makes it weaker than the other.

[bmanice]

Awesome thanks for the fast response. I was assuming it would be the same, but i wanted to get some outside opinions before i relayed my own to some colleagues.

[Alias]

If the implementations are both correct then both will be fine, however the cipher is not the only thing you need to worry about. The Block Cipher Mode of Operation is another thing you need to find out. For example if 7zip is using EBC (Electronic CodeBook) then you shouldn't use 7zip.

Only use an encryption program that lets you choose the cipher mode. There is no most secure cipher mode but if you have a choice then use CBC (Cipher-block Chaining)

If you want to see the difference then go here http://en.wikipedia.org/wiki/Block_cipher_modes_of_operation#Electronic_codebook_.28ECB.29 and scroll down until you can see the images.

[Guest Deleted_Account]

If the implementations are both correct then both will be fine, however the cipher is not the only thing you need to worry about. The Block Cipher Mode of Operation is another thing you need to find out. For example if 7zip is using EBC (Electronic CodeBook) then you shouldn't use 7zip.

Only use an encryption program that lets you choose the cipher mode. There is no most secure cipher mode but if you have a choice then use CBC (Cipher-block Chaining)

If you want to see the difference then go here http://en.wikipedia.org/wiki/Block_cipher_modes_of_operation#Electronic_codebook_.28ECB.29 and scroll down until you can see the images.

Don't quote me on this but according to TrueCrypt and other cryptography sites XTS mode is the best to use followed by CBC. Either way I don't trust zip file and encryption it has been implented badly before and I stick with TC as it is proven technology. I can't speak of 7-Zip but most of the time breaking zip files is rather easy but not sure if those were ciphered with AES-256 or that "zipcrypto" one. I have on many occasions recovered files from zip containers even when protected with a password (Windows default one; not even sure if they use encryption or not).

[Alias]

Don't quote me on this but according to TrueCrypt and other cryptography sites XTS mode is the best to use followed by CBC. Either way I don't trust zip file and encryption it has been implented badly before and I stick with TC as it is proven technology. I can't speak of 7-Zip but most of the time breaking zip files is rather easy but not sure if those were ciphered with AES-256 or that "zipcrypto" one. I have on many occasions recovered files from zip containers even when protected with a password (Windows default one; not even sure if they use encryption or not).

Don't quote me on this one either but I though that XTS was only for Disk encryption?

[Guest Deleted_Account]

Don't quote me on this one either but I though that XTS was only for Disk encryption?

You may be right. I only use Disk encryption and TC Volumes so Just what I know from experience. One thing of note I hate file encryption (like encrypting just one txt file for instance) I find it less secure (which it may or may not be) so I always use Virtual Volumes or Encrypted Partitions.