What encryption generates this type of text?

I'm trying to decode a DAT file produced by Yahoo Messenger, which looks similar to the text below which I generated by opening an exe in Notepad:

‹
‹N€9 tè…ÀtäÿFöt‹FŠ ‹V‹NˆÿFÿNëÿFH‰F3À9Ft9Ft  ö…³   ;Øtsj÷ël;Øt%‹F‹N¶Dÿj Pÿ5@aÐMè5  …À„þÿÿ…Ûuƒ} tÇEø   jEPÿvÿvÿuøÿ5DaÐMÿÐM…Àu,ÿÐM=Y  tjðë…ÛtjöXë<3Àf‹F,ÇF.   ‰Eë‹E‹N…Étÿv2PÿÑëƒ~$ t
‹N(f‰ƒF(ÿF 3À‰F_[É ÌÌÌÌ̃ù
u<r<Ÿ

I have tried few online tools that has various encryption al开发者_StackOverflow社区gorithm like Blow-fish, DES, MD5 1-Way and other normal encryption like leet speak, rot-13 etc, but i found the generated text is normal readable but not the original one. I think its AES or RSA or Triple DES. Actually i am working on a utility that will read the Yahoo Messengers archive of the local. But when i open the local , I found a DAT file, with encrypted text as above.

(UPDATE)

As per venkyduded article "yahoo uses a simple XOR algorithm to encode the messages (so much for security !!) ". Any good link on XOR rversing.

Any help would be highly appreciated.

Yahoo Messenger only encodes the data files. Take a look at http://www.venkydude.com/articles/yarchive.htm for details on the format of the data.

I don't think we can help you. Unfortunately strongly-encrypted data will be indistinguisable from random noise. I expect the NSA have statistics they can run on data to determine this but normal people like us are SOL.

Even if you did know the encryption mechanism you'd also need the key before you could make any sense of it, and again if the encryption is good enough it'd be very difficult / impossible to guess.

Your best bet would be to reverse engineer that part of Yahoo Messenger to see what it's actually doing and where it gets the encryption key from / where it stores it.

As per venkyduded article "yahoo uses a simple XOR algorithm to encode the messages (so much for security !!) ". Any good link on XOR rversing.

One would need to know what the original value was XOR against. One would also need to know some additional information, for example how many words were being XOR'ed at a time, the answer to your question is.

In order to get the inverse of an XOR value you have to simply XOR the value with the seed again.