Penetration Testing mailing list archives
Re: Determining the encryption used
From: iccs-abr () dsv su se
Date: 12 May 2006 13:43:02 -0000
To determine the encryption of a message should be really hard. That's the whole point of cryptography. Base64 is just an encoding so that's why is easy. Some classic encryptions leave a "trademark" signature on the cyphertext. In theory, modern encryptions should aim to produce cyphertext that is indistinguishable from random noise, however the truth is that far (not too far) from that. An effective cryptologist should have an arsenal of cryptanalysis techniques. I suggest you research cryptanalysis tools and techniques and try to decipher classic ciphers before moving to the likes of DES, AES, etc. The first and foremost effective way to analyze a cipher is to look for patterns and correlations (linguistic, statistical and mathematical) and try to find a weakness on either the key or the cipher (if you manage to know which one is it). So, if you only aim to find out what cipher was used, you can try to create samples of text (or any other type of message) encrypted with different ciphers and try to extract a statistical analysis on how a cipher encrypts and produces patterns independent of the cleartext and/or key in the ciphertext. Then analyze your cipher text and try to find a match. Sounds tedious, but the other approach involves mathematical analysis and Im not so good at that so I cannot say anything in the respect. ------------------------------------------------------------------------------ This List Sponsored by: Cenzic Concerned about Web Application Security? Why not go with the #1 solution - Cenzic, the only one to win the Analyst's Choice Award from eWeek. As attacks through web applications continue to rise, you need to proactively protect your applications from hackers. Cenzic has the most comprehensive solutions to meet your application security penetration testing and vulnerability management needs. You have an option to go with a managed service (Cenzic ClickToSecure) or an enterprise software (Cenzic Hailstorm). Download FREE whitepaper on how a managed service can help you: http://www.cenzic.com/news_events/wpappsec.php And, now for a limited time we can do a FREE audit for you to confirm your results from other product. Contact us at request () cenzic com for details. ------------------------------------------------------------------------------
Current thread:
- Re: Determining the encryption used, (continued)
- Re: Determining the encryption used Byron Sonne (May 12)
- Re: Determining the encryption used Peter Kosinar (May 12)
- Re: Determining the encryption used Tonnerre Lombard (May 12)
- Re: Determining the encryption used Tim (May 12)
- Re: Determining the encryption used Phoebe Tunstall (May 12)
- Re: Determining the encryption used Peter Kosinar (May 13)
- Re: Determining the encryption used Tim (May 13)
- Re: Determining the encryption used Tim (May 12)
- RE: Determining the encryption used Sahir Hidayatullah (May 12)
- Re: Determining the encryption used thomas springer (May 12)
- Re: Determining the encryption used Dotzero (May 12)
- Re: Determining the encryption used iccs-abr (May 12)
- RE: Determining the encryption used Bob Bell (rtbell) (May 12)
- Re: Re: Determining the encryption used cwright (May 12)