cipherday

Cipherday #75 · September 6, 2026

The answer to Cipherday #75

The full three-cipher chain from September 6, 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

“Great oaks from little acorns grow.”— traditional proverb

The largest things often begin from something easy to overlook.

The cipher chain

  1. Stage 1 · Caesar · Shift of 4

    Ciphertext

    Pievrmrk riziv ibleywxw xli qmrh.

    Decodes to

    Learning never exhausts the mind.

    Every letter was slid 4 places down the alphabet; sliding it back the same amount restores the line.

  2. Stage 2 · Substitution · Keyword “MEADOW”

    Ciphertext

    Ouoqy ailtd cmr m rfiuoq ifkfkb.

    Decodes to

    Every cloud has a silver lining.

    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 “SPHINX”

    Ciphertext

    Yglig lszz nele apbgiw pjwekk vywj.

    Decodes to

    Great oaks from little acorns grow.

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