The Archive

Flags on the pad

Easy. Semaphore. Flags as clock positions, letters A–Z around the circle.

Bacon on the desk

Medium. Baconian cipher. Five a/b symbols a letter. A=aaaaa.

Five and eight

Medium–hard. Affine cipher. E(x) = (5x + 8) mod 26. A=0.

Five by five, good news

Easy–medium. Polybius square. I and J share a cell.

Pigpen at the chopsticks

Easy. The old Masonic alphabet. One word.

Playfair, Tesla

Hard. Playfair square. Keyword TESLA. I/J share. X fills doubles.

Read the columns, rail

Medium. Columnar transposition. Keyword RAIL.

Star key on the Gulf

Medium. Vigenère. Keyword STAR, repeating.

Taps from the tower

Easy–medium. Prison tap code. Five-by-five, I and J share.

Three rungs to steel

Easy. A word ladder. Change one letter at a time.

Three ships, three places

Harder. A tiny logic grid. This week’s Starship traffic.