WebApp Sec mailing list archives
Re: Which encryption algorithm used?
From: "Adam Tuliper" <amt () gecko-software com>
Date: Wed, 26 May 2004 10:13:27 -0400
Im not sure how visual studio (or java for that matter) would come into play in this at all. I'll assume you mean using for ex. the dotnet framework. In that case there are several managed classes and then some crypto api provider classes. Considering that your ciphertext is a function of your plaintext and the algorithm, your cipher text can be a complete seemingly random piece of data. Sure it can be cryptanalyed (frequency analysis, etc - see Bruce Schnier's Applied Cryptography for an excellent resource), but to look at what _should_ be a random seeming piece of data and determine the algorithm would seem to be a failure of the algorithm itself. There are many many algorithms out there and to use length of a ciphertext block means nothing except that is may be using padding on the end to reach a certain block size. If its a feedback algorithm, feeding the results into itself again.. good luck. Heres a neat project: http://burtleburtle.net/bob/crypto/findingc.html Note in the first sentence: "If the block cipher has, oh, addition as well, the results of this program are amazingly worthless" On Wed, 26 May 2004 15:52:10 +0300 "Marian Ion" <marian.ion () e-licitatie ro> wrote:
Hello all, If you would use Visual Studio or java, it would be quite easy (built-in classes), and there are many examples on the web. Otherwise, a little bit difficult, because you would have to know everything about several encryption and hashing algorithms... Marian Ion. -----Original Message----- From: stevenr () mastek com [mailto:stevenr () mastek com] Sent: Wednesday, May 26, 2004 10:41 AM To: webappsec () securityfocus com Subject: Which encryption algorithm used? Hi all Is it possible to identify the encryption algorithm used by looking at the format of the encrypted string? Of course I understand we not may be 100% accurate but there could be a chance we hit home. To give an example, probably a 32 character string could be a MD5 hash, and a string ending with == could be base 64 encoding. Is there any tool which can give a list of possible algos used, if provided with the encrypted string? anyone know of any site which has info on this ? Thanks in advance Steve MASTEK "Making a valuable difference" Mastek in NASSCOM's 'India Top 20' Software Service Exporters List. In the US, we're called MAJESCO
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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)