Cipherday #73 · September 4, 2026

The answer to Cipherday #73

The full three-cipher chain from September 4, 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

“An investment in knowledge pays the best interest.”— Benjamin Franklin (Poor Richard’s Almanack, 18th century)

Franklin the printer weighing learning as the surest return.

The cipher chain

1. Stage 1 · Caesar · Shift of 15

   Ciphertext

   Iwt rjgt udg qdgtsdb xh rjgxdhxin.

   Decodes to

   The cure for boredom is curiosity.

   Every letter was slid 15 places down the alphabet; sliding it back the same amount restores the line.

2. Stage 2 · Substitution · Keyword “WANDER”

   Ciphertext

   W bej nwkkls ae mlifqced vfsclts rpfnsflk.

   Decodes to

   A gem cannot be polished without friction.

   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 · Rail-fence · 3 rails

   Ciphertext

   Antt wgatb etnivsmn nkoldepy h etitrs. eeine sesne

   Decodes to

   An investment in knowledge pays the best interest.

   The letters were written in a zig-zag across the rails, then read row by row; re-weaving the zig-zag recovers the order.