# Tag Archives: decipher

## Secret Code II

‘X’ is for… ??

I’ve written about secret codes before. The Pigpen cipher was pretty simplistic, almost more a child’s game, but the Playfair cipher was a bit more interesting. That one came from a murder mystery novel by Dorothy L. Sayers. Today I thought I’d show you another simple code from another mystery novel.

1829 2125 0038 2226 1600 2125 0027 1722 4200 1829 1600 4219 2518 1617 1900 4122 3916 3200 3700 4019 0025 2016 0028 1724 2718 2241 4400 2118 0020 2516 2500 1829 1600 1819 2316 1517 2118 1617 0038 2226 1643 0015 2921 3829 0030 2025 1800 2425 2521 2841 2500 4120 4240 1617 2500 1822 0018 2916 0031 1619

Stop! See if you can decode the above before continuing.

## The Playfair Cipher

Code master Wheatstone

Among my second tier interests are murder mysteries, detective stories, and cryptography. The first typically includes the second, but there are many detective stories that don’t involve murder. Two of my favorite detectives, Spenser (by Robert B. Parker) and V.I. Warshawski (by Sara Paretsky), often have cases not involving murder.

The third interest I listed, cryptography, doesn’t usually coincide with the first two, but it did play a role in a recent locked-room murder mystery involving the delightful amateur detective Lord Peter Wimsey (by Dorothy L. Sayers). While I’ve always enjoyed secret codes, I’d never heard of the cipher Sayers used — the Playfair cipher.

It dates back to 1854, and is kind of cool, so I thought I’d share it.

## Secret Code

When I was a high school kid, my dad and I sometimes played a game where one of us would make up a secret code, write a message in that code, and the other would try to decipher the message. We generally used simple substitution ciphers, so it was an exercise in letter frequency analysis and word guessing.

There’s a cute secret code I found in a book back then that really stuck with me because of the neat way it looks. It also stuck with me because it’s so simple that once you learn it, you really can’t forget it.

So for some Saturday fun, I thought I’d share it with you.