----- Original Message ----- > From: Graham Leggett <[email protected]> > To: "[email protected]" <[email protected]> > Cc: "[email protected]" <[email protected]>; Roberto Spadim > <[email protected]> > Sent: Saturday, August 17, 2013 9:46 AM > Subject: Re: How to securely encrypt identical files to identical ciphertext? > > On 17 Aug 2013, at 06:03, Unga <[email protected]> wrote: > >> My encrypted file is with you. It is encrypted without a salt. I'm > scared you may use a sophisticated system to decrypt it and read the > sensitive > info. I use a per file not guessable 150 character password. This password is > not repeated, only reuse on identical plaintext files only. >> >> >> I want to understand is it any easy for you to decrypt it than a salted > encrypted file? > > The purpose behind the salt is to make sure two identical plaintexts > encrypted > with the same key give different values for the cyphertext. This remains > important in your case because your file is actually a series of plaintexts > of a > given block size one after the other, and if you have regular data in the > plaintext you will have regular data in the cyphertext without a salt. > > What you might do when you generate your unique random passphrase is at the > same > time generate a unique random salt, and store the two together. > > Regards, > Graham > --
Thank you, Graham. This is definitely a good idea. Unga ______________________________________________________________________ OpenSSL Project http://www.openssl.org User Support Mailing List [email protected] Automated List Manager [email protected]
