>> Decryption Challenge <<

[Lonewolf10]

Originally Posted by RedskullDC

Ok...

Repeating sequence of bytes, $2C in length:

43444937 434E493E 435F4916 43784957 43E2483A 42F74B8A 472C4E17 48D65B86 5D0F79CE 0C00C977 8CCA4932

or 11 long words.

Each long word from the Encrypted image data is XORed with the corresponding long word from the list above then rotated by 16 ( or 68K "SWAP" ).

Example:

Encrypted data offset $AA8: $BC04493C
XOR with corresponding long word: $43444937
= $FF40000B
after swap: $000BFF40

Data in RAW Image file at $AA8: $000BFF40

That was fun

Cheers,
Red

Apologies, I thought I had already confirmed that you were correct in decrypting it, but alas 2 months later I see that I didn't

The 11 longwords are actually 4 characters (which never change) that have been masked by 2 (numerical) words calculated using the fibinacci sequence (starting values 0 & 3, thus first word is masked by 3 and second word is masked by 6). That is why the sequence repeats every 11 longwords (as the fibinacci sequence exceeded 65535).


Regards,
Lonewolf10

[pmc]

Kind of in the spirit of this thread and it might interest someone...

I visited Bletchley Park recently where they cracked the Enigma code during WWII.

I found the Enigma machine itself, and how it enciphered messages, to be pretty interesting so... I read some stuff about it and then coded my own Enigma inspired cipher routine, in asm of course.

Hopefully it's a bit stronger than the Enigma - there's more possible combinations I think - although I lack the mathematical skills to define just how strong in any meaningful statistical terms.

Anyway, if there is actually anyone out there who might enjoy, enjoy.

EDIT: I went away and totally recoded my cipher and turned it into a complete command line driven tool. Released to the coders releases section.

[Lonewolf10]

Doh...

I did actually look at the code when you had it up but forgot to reply. It certainly looks cool and I had thought about creating a CLI version, but you have already done it!

Will check it out later.

[Don_Adan]

Other thread about MoonQuake dercyption:

http://www.mameworld.info/ubbthreads...=&sb=5&o=&vc=1