Cipher missions – decrypt the secret messages

Decrypt secret messages, discover keys and complete increasingly difficult online cryptography puzzles across seven cipher series.

Cryptography puzzles built around reasoning

From first clue to layered finale

Each six-part series introduces a method, then removes support until the finale combines two encryption layers. Progress depends on understanding the cipher rather than cycling through answers.

Skills you practise

Look for patterns, use keys and test deductions across Caesar, Vigenère, Atbash, Polybius, rail fence, Hill and Enigma puzzles.

Start a mission

Choose a series and recover its plaintext. The cipher laboratory and printable sheets can support your work, but the deduction remains yours.