| Clue | Source | Date |
|---|---|---|
| Cryptologists in action | ||
| Bletchley Park workers | The Telegraph Cross Atlantic | 21 Mar 2025 |
| Signal-converting devices | ||
| Devices sent to Little Orphan Annie Secret Society members | ||
| Crackers and fish consumed by The Harts? | Irish Times Crosaire | 27 Sep 2021 |
| Ones getting the message | New York Times | 28 Mar 2021 |
| Readers of secret messages | Thomas Joseph | 22 Jun 2020 |
| Does without fish suppers initially? They're crackers! | ||
| Enigma solvers | ||
| Cryptogram solvers | ||
| Keys of a kind | ||
| Specialists of a sort | ||
| Cryptanalysts. |