Re: PLEASE HELP - How do I include OpenSSL in my code? <OT: Cryptographic laws>

Malcolm said:

"Richard Heathfield" <invalid@xxxxxxxxxxxxxxx> wrote in message
True; of course, most people who hear that believe that ciphertext[i] =
plaintext[i] ^ 5 is a "reasonably secure cryptosystem".

And so it is, provided nobody actually tries to crack it (which, again,
is true of most cryptosystems!).

When people do try to roll their own, it is sometimes embarrassing to see
just how quickly they can be broken. A guy I used to work with came up
with
what he thought was an uncrackably complex scheme. He had spent several
days designing it. He gave me no algorithm, just some ciphertext, and it
took me about ten minutes. <sigh>

But if you are scanning every email sent in the country, for the string
"Mr Vladimir orders three quarts of cheese", then those ten minutes are
prohibitive.

Yes, but this was (almost) twenty years ago, by hand. With a computer, it
would have taken approximately three xesoseconds[1] to crack the code -
which, despite all its superficial complexity, was a mono.

Two common mistakes made by bozocryptographers are:

(1) they think that, to get the plaintext, the cryppies are required to
reverse-engineer the actual (secret) cryptosystem devised by the
cryptographer;
(2) they don't realise that two (or even a great many more than two)
substitution schemes are basically the same as one substitution scheme and
can be solved as if they were one.

Well, it was almost twenty years ago, so I think I've known enough Andrews
that I can call the guy Andrew (his real name) without fear of embarrassing
him. What Andrew had done was to set up a monoalphabetic substitution
cipher (A = R, B = K, C = Z, whatever). He had then replaced each letter by
an entire word beginning with that letter. He then replaced the word by a
picture representing the word. And he then replaced the picture by a
four-digit number. He thought there was no way I'd be able to even guess
that pictures were involved (which was true!), and that therefore I would
be unable to decipher the message (which was not!).



[1] abbrev for "oneofthosenewfangledprefixesoseconds"

--
Richard Heathfield
"Usenet is a strange place" - dmr 29/7/1999
http://www.cpax.org.uk
email: rjh at above domain (but drop the www, obviously)
.

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