From: "Iñaki Baz Castillo" <ibc@...>
Date: 2012-12-20T18:52:08+09:00
Subject: Re: Efficient way to encode a string with a secret string and recover it

2012/12/20 Iñaki Baz Castillo <ibc@aliax.net>:
> Hi, basically I receive a string generated by a user, then "encode" it
> using some secret string I own and pass the result to other user, and
> when I receive such a resulting string I must be able to decode it
> using my secret string (but no other should be able to decode the
> resulting string without knowing my secret key. This is:
>
>
> original_string = "test"
>
> secret_key = "ABCD"
>
> modified_string = HASH_FUNCTION(original_string, secret_key)
>
> original_string = UNHASH_FUNCTION(modified_string, secret_key)
>
>
> Any suggestion for the above HASH_FUNCTION and UNHASH_FUNCTION? I
> would like it to be something really efficient.


I've found the Crypt [*] library but it seems not adapted for Ruby
1.9. And I would prefer a C based Ruby extension.


[*] http://crypt.rubyforge.org/


-- 
Iñaki Baz Castillo
<ibc@aliax.net>