I don't know if you guys have seen Andrew K's page on Cryptographic Curiosities... But it shouldn't be too hard to include for instance the RSA algorithm in Zope, when it can be expressed in four lines of Python: #!/usr/local/bin/python from sys import*;from string import*;a=argv;[s,p,q]=filter(lambda x:x[:1]!= '-',a);d='-d'in a;e,n=atol(p,16),atol(q,16);l=(len(q)+1)/2;o,inb=l-d,l-1+d while s:s=stdin.read(inb);s and map(stdout.write,map(lambda i,b=pow(reduce( lambda x,y:(x<<8L)+y,map(ord,s)),e,n):chr(b>>8*i&255),range(o-1,-1,-1))) According to his example, it can be used like this: echo 'Top secret message.' | rsa.py 10001 1967cb529 > ciphertext cat ciphertext | rsa.py -d ac363601 1967cb529 Fuller description can be found on http://starship.skyport.net/crew/amk/writing/crypto-curiosa.html (And just out of curiosity: Is it a crime to view this web page outside the US? ;) -- Magnus Lie Hetland www.pvv.org/arcadia <arcadia@pvv..org>