I have searched through the boards and google but not much chance yet to find a decent way of encryption and decryption algorithm explain in details

can anyone give me a link or something where i can find how those neat encryption and decryptions algorithms are implemented ?
Posted on 2006-04-19 22:48:09 by XCHG
A link to more resources ;)... http://www.asmcommunity.net/board/index.php?topic=20060.0
Posted on 2006-04-19 23:13:06 by rea
Off my head,

I can only remember a few like

DES
RC6
AES
TEA

You would have to google for more encryption system (Take a look at the links in the thread started by rea).  ;)
Posted on 2006-04-21 12:40:13 by roticv
RC6, AES/Rijndael and TwoFish are worth checking out. DES can be bruteforced in reasonable time. TEA is weak in it's original implementation, but x-tea is sorta okay... I'd stick to RC6 or Rijndael myself, though.
Posted on 2006-04-21 12:45:42 by f0dder
Of course, DES can be bruteforced in reasonable time - that's why they needed AES. I think I will try coding one of the encryption scheme when I have the time...

Bah... I always seem to have so little time.
Posted on 2006-04-22 01:42:53 by roticv
Birna Gladman already has Assembly code available for AES: http://fp.gladman.plus.com/AES/
Posted on 2006-04-22 02:49:51 by f0dder
Thanks for the link, f0dder.  ;)
Posted on 2006-04-22 06:38:20 by roticv
thank you all for the links. i think now i've got another question.

Is using ROR and ROL recommended in encryption ?
Posted on 2006-04-23 22:05:17 by XCHG
blowfish is ok too thats what i use.
Posted on 2006-04-26 21:56:43 by Qages

thank you all for the links. i think now i've got another question.

Is using ROR and ROL recommended in encryption ?


ROR and ROL are used in some ciphers. Rather than trying to build your own, try and use some prebuilt ones like the ones listed above. If you are wanting to learn Cryptography and/or want to develop your own, then I suggest you spend a few bucks and buy some decent books on the topic. When you first start out, you aren't going to be able to develop anything that will be remotely secure so I don't suggest trying to build your own for a release application.

When starting out, your primary focus should be in the study of three types of ciphers; Substitution Ciphers, Transpositional Ciphers, and SubTransy Ciphers (one which uses both). A subsititutional cipher simply changes the plain text (PT) against a cipher table to create the cipher text (CT). Two common examples of this are the XOR Cipher, which just xor's each byte with a key value, and the SlideKey Cipher, which preforms a choosen basic algorithmic calculation on the byte against a key value which increments or decrements depending on the implementation. A transpositional cipher changes the ordering of the bytes as to obfuscate the PT, one example of this is to swap the hiword and loword values of a byte. A subtansy cipher is one which incorperates both techniques above, changing the PT byte's arrangement as well as substituting the values against a key table. I suggest taking time and learning to develop several of these types of ciphers before venturing into advanced techniques such as ECB Ciphers. As for recommended reading, check out the "Applied Cryptography" series of books their really good.

Regards,
Bryant Keller
Posted on 2006-04-26 22:36:47 by Synfire
Uh that's all i wanted to know
thanks Synfire and everyone
Posted on 2006-04-27 21:04:06 by XCHG