MCrypt is a replacement for the old crypt() package and crypt(1) command, with extensions. It allows developers to use a wide range of encryption functions, without making drastic changes to their code. It allows users to encrypt files or data streams without having to be cryptographers. Above all, it allows you to have some really neat code on your machine. :)
The companion to MCrypt is Libmcrypt, which contains the actual encryption functions themselves, and provides a standardized mechanism for accessing them.
This web page is temporary, until a better one can be written.
|Algorithm||Encumbered||Block Size||Key Type||Notes|
|Arcfour||Probably not||Stream||Secret||Name is derived from "Alternative RC4". It is a mathematical clone of RC4, apparently to bypass the IP limitations of the original formulation. Arcfour is usually treated as unencumbered, and seems safe to regard as such, in general. IP interpretations at a given time or place may be different. If it is reclassed as encumbered, it will be removed from the main code.|
|Rijndael||No||128, 192, 256||Secret||AES if used in 128-bit mode|
|Skipjack||Doubtful||64||Secret||External module. Written by NSA for Clipper chip. Origins are murky.|
Modes of Operation:
It should be remembered that not all modes will work with all block ciphers, either because of implementation constraints or design constraints.
Proposed extensions and modifications
Any algorithm found to be covered by IP that conficts with the GPL cannot be a part of mcryptlib as standard. I believe the previous maintainer kept such material seperate, to avoid license contamination. This will remain the case, until or unless the owners of the algorithms remove conflicting restrictions.
Open Letter to Industry
Any comments or suggestions, relating to these pages or to the project should be e-mailed to: John Smith, the current maintainer for mcrypt and mcryptlib.