Decryption Help

I've been given the task of rewriting an old VB6 app using C#. The client was never given the source code, and the company that wrote if for them originally went out of business years ago. The VB6 app runs off an access database, which I have converted to SQL Server 2005.

The only problem I've encountered is that some, but not all, data is encrypted. I have no idea how I'm supposed to decrpty this data to find the original values. The only help the client could give me is this:

yfgJ ofcahtojtI
=
Birmingham Road

Not much to go on really...

Any suggestions on where to start? Have I realistically got a chance in hell of reversing the encrypted values?

Thanks

First, reverse the encrypted string.

Second, a capital 'I' translates to a B
a lower case 't' is a lower case 'i'
a lower case 'j' is a lower case 'r'

...and so on.

That's pretty weak encryption, although its easier when you know what its supposed to translate to. Once you've worked out what each character is, it might be that there is a calculable formula to do it, or there might just be a lookup table somewhere which simply switches one character for another.

Jeesh - I'm embarrased that I didn't even see the reversing!

I'd stupidly assumed it would be using a strong algorithm.

Thanks GFK.

Yeah, the space kinda gave it away. Also the position of the upper case characters. So if you're going to come up with your own variation of this for your own encryption, you might want to address that (i.e. sometimes switch an upper case letter for a lower case one, and make it so Space = 'k' or something).

It's proving easy now. It looks like it's a simple letter matrix. I'm going to use .Net's encryption in the new version, so there'll be none of this weak crap (even though it had me stumped).

Cheers mate.

One man's stump is another man's firewood ;)
I kinda noticed the same thing as Gfk when I first glanced upon it .. guess its good to get a second opinion if you're stuck ;)

Absolutely.

I just (wrongly) assumed that the original developers were using a standard form of secure encryption. I gave them too much credit and overlooked the obvious!

"Obfuscation through reputation" ;)

This is eerie... It reminded me of the BOFH.

Anyone remember this?
http://members.iinet.net.au/~bofh/newbofh/bofh4oct.html

"Lowercase and all words spelt backwards?"


Heh heh heh!