HTS Basic Mission 6 Solution

So as per the mission You have recovered his encrypted password now just to find the algorithm to decrypt it.  You’ll notice that if you encrypt “aaaaa” it gives you “abcde”. This encryption simply adds the character number to the character, starting at 0.
You can use http://www.asciitable.com/ to find the progression of symbols.

Ex. if your encrypted password is “968d<56>” you need to subtract 1 from the second letter, 2 from the third, and three from the fourth, producing “956a”.

It isn’t obvious what < goes to, so use the link to find out that it is “8”. Continuing, you end up with “956a8007”, which correctly “encrypts” to “968d<56>”.

A little tool made to decrypt the password: http://www.2shared.com/file/Gslp58co/HackThisSite_DecryptME_Basic_6.html