Setting up Postfix and OpenDKIM

2015-08-10

Last week, I was presented with a fairly interesting challenge: add DKIM (via OpenDKIM) support to our mail servers (running Postfix). Given that I’ve never actually worked on a mail server before, it sounded fun. 😄

Caesar cipher

2014-03-12

Here’s a 5 minute¹ coding challenge from Programming Praxis:

A caeser cipher, named after Julius Caesar, who either invented the cipher or was an early user of it, is a simple substitution cipher in which letters are substituted at a fixed distance along the alphabet, which cycles; children’s magic decoder rings implement a caesar cipher. Non-alphabetic characters are passed unchanged. For instance, the plaintext PROGRAMMINGPRAXIS is rendered as the ciphertext SURJUDPPLQJSUDALV with a shift of 3 positions.

– Source: Wikipedia, public domain

An optimal alphabetizing cipher

2013-01-25

Here is today’s /r/dailyprogramming challenge: Generate a simple substitution cipher such that the maximum number of words in a given dictionary of six letter words (there are 7,260 of them) are encoded as strings in alphabetical order.