Cipherday #76 · September 7, 2026

The answer to Cipherday #76

The full three-cipher chain from September 7, 2026, the public-domain quote it hid, and how each cipher worked. Today’s chain stays sealed until it becomes a past day.

The revealed quote

“Simplicity is the ultimate sophistication.”— attributed to Leonardo da Vinci

A Renaissance line prizing the plain over the ornate.

The cipher chain

1. Stage 1 · Caesar · Shift of 12

   Ciphertext

   Tabq ue ftq ftuzs iuft rqmftqde.

   Decodes to

   Hope is the thing with feathers.

   Every letter was slid 12 places down the alphabet; sliding it back the same amount restores the line.

2. Stage 2 · Substitution · Keyword “GALLEON”

   Ciphertext

   Tco brgss ds giwgys brookor mk tco mtcor sdeo.

   Decodes to

   The grass is always greener on the other side.

   A keyword scrambled the alphabet into a fixed cipher alphabet, so each letter always stands for the same partner — letter frequency gives it away.

3. Stage 3 · Vigenère · Keyword “HORIZON”

   Ciphertext

   Zwdxkwpphp qr hul icbhanas jwovvzhzkzhvvb.

   Decodes to

   Simplicity is the ultimate sophistication.

   A repeating keyword shifted each letter by a different amount, which is what lets one letter encrypt two ways; the right keyword resolves it.