WebApp Sec mailing list archives
RE: Which encryption algorithm used?
From: "Pitts, Christopher C." <Christopher.Pitts () HaverstickConsulting com>
Date: Thu, 27 May 2004 09:59:15 -0500
products that support muliple encryption algorithms (such as PGP/GPG email products) probably have to include this information in the file somewhere (header or footer or in the public key package, I think in would be in the key package as if you tell the sender to use a certain algorithm it should also help with interoperability between vendors products if they support different sets of algorithms with only one or two in common) so the recipient can decrypt it properly.
Actually, even many (most?) symmetric encryption products do this. Pop open a file encrypted with something like mcrypt and you'll see what I mean. Mcrypt, interestingly enough has an option (--bare IIRC) that will strip this out, but then requires you to specify the encryption cipher upon decryption as mcrypt will be unable to detect the cipher used. As others have mentioned, in a "perfect" crypto algorithm the crypt stream would be indistinguishable from random noise. If it is not, then it is possible that that algorithm is susceptible to a frequency analysis attack using chosen ciphertext, but that's just my opinion. Christopher
Current thread:
- Which encryption algorithm used? stevenr (May 26)
- RE: Which encryption algorithm used? Marian Ion (May 26)
- Re: Which encryption algorithm used? Adam Tuliper (May 26)
- Re: Which encryption algorithm used? exon (May 26)
- Re: Which encryption algorithm used? exon (May 26)
- <Possible follow-ups>
- RE: Which encryption algorithm used? Pitts, Christopher C. (May 26)
- Re: Which encryption algorithm used? John Borwick (May 26)
- Re: Which encryption algorithm used? windo (May 27)
- Re: Which encryption algorithm used? Adam Lydick (May 27)
- Re: Which encryption algorithm used? exon (May 31)
- Re: Which encryption algorithm used? John Borwick (May 26)
- RE: Which encryption algorithm used? Pitts, Christopher C. (May 27)
- RE: Which encryption algorithm used? Tom Arseneault (May 27)
- RE: Which encryption algorithm used? Michael Silk (May 27)
- RE: Which encryption algorithm used? Marian Ion (May 26)