----- Original Message ----- > From: Matt Caswell <[email protected]> > To: [email protected] > Cc: > Sent: Friday, August 16, 2013 4:10 PM > Subject: Re: How to securely encrypt identical files to identical ciphertext? > > On 16 August 2013 16:46, Swair Mehta <[email protected]> wrote: >> On 16-Aug-2013, at 7:49 AM, Unga <[email protected]> wrote: >> >>> Hi all >>> >>> I have a requirement to encrypt files, in such a way identical files > should generate identical ciphertexts. >>> >>> I plan to use aes-256-cbc cipher with 128-byte long non-guessable > password per input file. Identical input files will be provided with > identical > passwords. >>> >>> 1. Is it no salt the way forward for me? >>> >>> >> Identical salts(ivs) should work. No salt works as well. >> > > This would have the effect that two files which were identical at the > beginning for the first x number of blocks (but different afterwards) > would encrypt to the same first x number of blocks. > > Matt >
Hi Thanks for the reply. I have mentioned I use the same password only if files are identical. I get vastly different two AES encrypted cipher texts for two very large files with only one character different. So is my approach any less secure? Unga ______________________________________________________________________ OpenSSL Project http://www.openssl.org User Support Mailing List [email protected] Automated List Manager [email protected]
