Decoding puzzle

[Phil-T4]

I'm feeling pretty pleased with myself as it only took me 3 hours to work this out..

Here is your challenge if you wish to accept it

Here are two encoded VIN numbers that i read from different EWS ecu's.

1C29B6D371D64B0CD088241041
1C29B6D345544C896046084046

Here are the decoded VIN's for the above

SARRJSTPB3D289111
SARRJHLHCYM162416

How is it done?

Good Luck
Phil

[Steve916]

You take the first number and then, +32, x12, /15, -65, and add a SARR to the front
Don't know mate, but looks impressive

[Phil-T4]

yep 1C = S

[Avulon]

My guess?
The encoded VIN numbers are in hex, but do not directly decode to the characters, so either a constant (hex) number is added to the encoded form (or multiplied by the encoded form) to give a hex string which will directly decode using utf-16.

Either it's that or it's even more complicated, and I can't think of another way of doing it at the moment (not with the info given anyway).

[MG Tom]

PA Soft?

[Georgies Dad]

If you turn the letters into numbers using place in alphabet,then multiply each number together,then add 2 divide by 100+49 you get a long number when translated by turning the numbers back to letters it is an anagram which reads:

I have not got a clue either,try again later!!!


PS The dog has solved it,answer is woof woof woof followed by another woof

[Steve916]

Originally Posted by Avulon

My guess?
The encoded VIN numbers are in hex, but do not directly decode to the characters, so either a constant (hex) number is added to the encoded form (or multiplied by the encoded form) to give a hex string which will directly decode using utf-16.

Either it's that or it's even more complicated, and I can't think of another way of doing it at the moment (not with the info given anyway).

I tried converting from Hex to String too but wouldn't work out as a straight conversion, so maybe you're right, a constant has to be added

Originally Posted by w44nty

If you turn the letters into numbers using place in alphabet,then multiply each number together,then add 2 divide by 100+49 you get a long number when translated by turning the numbers back to letters it is an anagram which reads:

I have not got a clue either,try again later!!!


PS The dog has solved it,answer is woof woof woof followed by another woof

[sikelsh]

Don't know how you did it, but I have a card game at the weekend if you care join me Mr Hoffman

[Phil-T4]

Yes its hex and you need a table..
0h to 9h = "0" to "9"
0Ah = "A"....to......23h = "Z"

To produce SARR, the result from below is matched to the character using the table....

[S] = byte[0]
[A] = byte[1] / 0x04
[R] = (byte[1] % 0x04 * 0x10) + (byte[2] / 0x10)
[R] = ((byte[3] / 0x10) + (byte[2] % 0x10 * 0x10) / 0x04)

/ is divide
% is the remainder value from a divide
* is multiply

[Avulon]

OK, that's tortuous enough, what I'd like to know is what lead you to the solution? I mean, it's not exactly intuitive. Was there some clue gleaned from elsewhere? However you got there, well done! I'd never have thought of something quite that complicated, (nearly but not quite)

Just getting my head around what I'm doing for work at the moment is enough to fry my head with the current heat wave as well.(you should try getting your head round complex 'business logic' - an oxymoron if ever there was one!)