Oh, say, PGP, and RSA public key Cryptosystems are simple, with primes $q$ and $p$; Call the product of one less than each of them $k$ I pick $d$ and $e$, whose product is $1\bmod k$.
Now I just publish $d$, and the product $qp$,
You raise $d$ to the power of message block $b$;
Take that modulo $pq$ and send it to me.
And I'll use it as the exponent of private key $e$.
Now this program can fit into three lines of code, Using perl and dc, though the logic's distorted. Cryptographic machines are a weapon of war, And the government says they must not be exported.
Make a barcoded card, or if you are a bard
run the code through a modem, it's not very hard.
\spoken{\quotation{
Now, if I were being mean I'd stick some modem tones in here}}
Then this song would be a munition, its music you could never take
From the land of the free, and the home of the brave.
The description of the RSA public key crpytography algorithm is mathematically accurate; though it's worth noting that any practical implementation will do the exponentiation and modules in a single operation. Perhaps the only obscure point occurs when specifying that $de \equiv 1 \bmod (p-1)(q-1)$. The twisted phraseology that defines $k$ as $(p-1)(q-1)$ is particularly kludgy, but what the hell, it scans.
http://thestarport.com/Steve_Savitzky/Songs/crypto.html
Automatically generated with flktran from crypto.flk.
$Id: crypto.flk,v 1.6 1999/09/01 05:40:06 steve Exp $