EXHIBITS > Telecommunication of the ancient Greeks >
Aeneas' cryptographic disc
A disc with 24 holes (one for each letter of the alphabet) on the periphery, one in the centre and one more defining the letter "A". The sender formed the message by passing a thin thread through the holes of the relevant letters and the receiver read it by removing the thread and noting the letters from right to left.
SOURCES: "Aeneas, Poliorkitika, 31"