| Rules |
| Ciphers |
| Programs |
| Encrypts |
| Protocols |
| Encryptions |
| Secret stuff |
| Ciphers, say |
| Morse et al. |
| Area and zip |
| Morse and zip |
| Kin of ciphers |
| Morse and area |
| Does a tech job |
| Message systems |
| Writes software |
| Secret messages |
| Secret writings |
| Things to crack |
| Creates software |
| Writes a program |
| Morse and others |
| Secret languages |
| Systems of rules |
| Hides the meaning |
| Works on programs |
| Sets of principles |
| Works on a program |
| Writes in C++, say |
| Cryptography topic |
| Systems of signals |
| Cryptography topics |
| Encrypts or ciphers |
| Housing regulations |
| Morse and zip, e.g. |
| Programmer's output |
| Sets of regulations |
| Writes in Java, say |
| They may be cracked |
| Penal and Napoleonic |
| Prepares punch cards |
| Cryptographer's study |
| Disguises the meaning |
| Secret communications |
| Some are made of bars |
| Writes in Java or C++ |
| They might be cracked |
| Cryptography creations |
| Creates a routine, e.g. |
| Cryptographers' studies |
| Does some computer work |
| Regulations for builders |
| Buildings often have them |
| Cryptographer's creations |
| They're sometimes cracked |
| Features of secret messages |
| Things broken by the C.I.A. |
| Crackers may be used on them |
| Things broken by Alan Turing |
| Does some computer programming |
| Computer programmers' expertise |
| Legacies of Morse and Hammurabi |
| Implements some website design, say |
| They're used to send secret messages |
| One if by land, two if by sea" and others |