Ciphers
Ciphers
Ciphers
Bifid in the factory
Hard. Bifid cipher. Keyword TESLA, period 5, I/J share.
Ciphers
Digits on the invite
Medium. Gronsfeld. Like Vigenère, but the key is digits. Key 2014. Spaces honest.
Ciphers
Flags on the pad
Easy. Semaphore. Flags as clock positions, letters A–Z around the circle.
Ciphers
Bacon on the desk
Medium. Baconian cipher. Five a/b symbols a letter. A=aaaaa.
Ciphers
Five and eight
Medium–hard. Affine cipher. E(x) = (5x + 8) mod 26. A=0.
Ciphers
Five by five, good news
Easy–medium. Polybius square. I and J share a cell.
Ciphers
Pigpen at the chopsticks
Easy. The old Masonic alphabet. One word.
Ciphers
Playfair, Tesla
Hard. Playfair square. Keyword TESLA. I/J share. X fills doubles.
Ciphers
Read the columns, rail
Medium. Columnar transposition. Keyword RAIL.
Ciphers
Star key on the Gulf
Medium. Vigenère. Keyword STAR, repeating.
Ciphers
Taps from the tower
Easy–medium. Prison tap code. Five-by-five, I and J share.