Deciphering my Dead Mother’s Cipher

My mom passed away in 2020, and in cleaning out her house I found her old diaries. Seventy five years ago, in 1948 at the age of 15, she wrote:

Ah, a puzzle. I like a good puzzle.

Some quick googling revealed it was a pigpen cipher. That’s where you take a 3×3 grid, like a Tic Tac Toe board, put a letter in each square, then use the square or “pen” that a letter is in to represent that letter. Of course, that only works for 9 letters. So you do it again, this time putting a dot in each square. That leaves 8 letters, so now you form an X, put a letter in each “pen” of the X, with or with out a dot.

And using that, I quickly decoded the first name, and got … JKLL LXNPNKON. Fail. She must be using a different way to map letters to pig pens. But what is it?

Well, in earlier entries she had crushes on hockey players and politicians. In fact, at age 14 she wrote “I like to imagine I am P.M. [Prime Minister] torn between 4 loves – 1. Cabinet Minister, 2. brother of first husband, 3. baseball big shot, + 4. French diplomat!” Two people in particular were Ontario Premier George Drew and Toronto Maple Leafs star Bill Ezinicki. And Bill fits the first cipher! Well, mostly. It has the right number of letters, the two Ls use the same symbol, and all three Is in Ezinicki use the same symbol. But the I in Bill uses a different symbol. Still it all fits too well to be a coincidence.

Another oddity is that every symbol has a dot. A standard pigpen cipher has 13 different shapes, then repeats those again with a dot inside to give 26 symbols. But if you only use the ones with the dot, you only have 13 symbols, so each symbol must represent two letters. You can see the L in Bill uses the exact same symbol as the E in Ezinicki.

I is the 9th letter, the last letter in the first pass when filling up the grid. What pattern means the center is filled last? A spiral inwards!

Well … that doesn’t work for B, E or C, the letters in Bill Ezinicki that are in the first nine of the alphabet. Back to square one.

So let’s look at the second name. Who’s wife would Ezinicki be running around with? It’s a dream so it could be anybody, but a reasonable guess is another team mate. The roster for the 1948 Toronto Maple Leafs shows nobody with a nine letter last name. Curses, foiled again.

With only 13 symbols, each symbol encodes multiple letters. So, just because the same symbol appears in two different locations doesn’t mean they’re the same letter. Think of the L and E in Bill Ezinicki. But the opposite is true, we hope: if two different positions use different symbols, they have to be different letters. So in that nine letter last name, the last seven letters all have to be different. And the first two letters have to be different than any of those last 7, save the seventh letter.

So let’s look at a list of common last names. The U.S. Census has a list of surnames occurring more than 100 times anywhere in the United States. It has 151,671 names. If you restrict to nine letter names, that leaves 14,424, which is still a lot. The most common is Rodriguez. And while the last seven letters of that name are all different, the first letter is the same as the fourth, namely R, but they use different symbols.

Making sure different symbols represent different letters leaves 2,160 names, the most common of which is Dominguez. There’s no pattern that I can see in the most common names.

So we need more information. The last letter uses the same symbol as the I in Ezinicki. Of course, it doesn’t have to represent an I, but what if it did? Here are the 10 most common surnames:


Now we’re getting somewhere! If it ends in an I — a big if — the last three letters are probably SKI. However, there’s no real pattern in the earlier letters. So once again, we need to look at the problem differently.

Let’s try putting the known letters in pens, and see if we can see any patterns. We won’t add the SKI since that depends on an assumption, but we’ll do it for all of Bill Ezinicki:

Well, the B is in the upper left, the same spot as A in the standard encoding. And it seems most natural for a pattern to start in the upper left with A. If A & B are the two letters mapped to the upper left, that suggests C & D are next, in the upper middle, then E & F in the upper right, and so on.

And that mostly works! The I and L in Bill are in the wrong place, although interestingly, they’re just missing a top line in their symbol. But all the other letters fit. If we use this with the second name, we get:

W A K K Y | S S A M O W S K I
X B L L Z | T T B N P X T L J

Perhaps you can see it by just looking at the above, but if not, some simple filtering of the surname list gives us: Stanowski. Wally Stanowski played for the Leafs the season before, 1947 – 1948.

Also, as I was researching this post, I found a variant of the pigpen cipher where the location of the dot distinguishes the two letters: left for the first, right for the second. And if you look at, say, the ST at the start of Stanowski, you’ll see the first dot on the left, second on right.

It’s fun exploring my Mom’s old diaries, which span over 30 years of her life, up to when I was 9 years old. She never used a cipher again, but I’m glad I got to figure out the dreams of a 15 year old girl in 1948. I’m sure she never pictured her son using a computer to crack it. The existence of the first computer, ENIAC, was only revealed two years earlier in 1946. And it would be over four more decades until the World Wide Web was opened to the public, and another decade until Wikipedia and search engines made it possible to find old Maple Leafs rosters and learn about Pigpen ciphers.

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