| Disguise the meaning | 20 |
| Cryptoquote, really | 19 |
| Cryptographers break it | 23 |
| Cryptographer's secret | 26 |
| Cryptogram key | 14 |
| Cracking target | 15 |
| Cracking candidate | 18 |
| Computer programmer's work | 30 |
| Computer language, e.g. | 23 |
| Commercial _____ | 16 |
| Collection of laws | 18 |
| Cipher or encipher | 18 |
| Building regulations | 20 |
| Building inspector's expertise | 34 |
| Building contractor's study | 31 |
| Bottom numbers on an envelope | 29 |
| Body of regulations | 19 |
| Body of national laws | 21 |
| Black-chamber concern | 21 |
| Binary ___ | 10 |
| Area or Morse | 13 |
| Agent's aid | 15 |
| A masking term (for) | 20 |
| "The Da Vinci ___" | 28 |
| "Bar" or "airport" follower | 47 |
| 'The Da Vinci ' | 23 |
| ''One if by land, two if by sea,'' e.g. | 55 |
| ''Bar'' or ''airport'' follower | 63 |
| --- blue (medical emergency) | 28 |
| ___ of silence (what a snitch breaks) | 37 |
| ___ of laws | 11 |
| __ of ethics | 12 |
| Cryptologist, often | 19 |
| Cryptographer, often | 20 |
| Classified | 10 |
| Encrypted | 9 |
| Like some messages | 18 |
| Like secret messages | 20 |
| Ciphered | 8 |
| Like wartime messages | 21 |
| Like cryptograms | 16 |
| Like many wartime messages | 26 |
| Like a cryptogram | 17 |
| Wrote software | 14 |
| Wrote an app | 12 |
| Unreadable | 10 |
| Like DNA | 8 |
| Hard to crack | 13 |
| Written in a secret language | 28 |
| Scrambled, in a way | 19 |
| Requiring cracking, perhaps | 27 |
| Put into dots and dashes | 24 |
| Put into bars, say | 18 |
| Not easy to read | 16 |
| Needing deciphering | 19 |
| Needing cracking | 16 |
| Marked for identification | 25 |
| Like U.S.A.F. messages | 22 |
| Like some wartime messages | 26 |
| Like some secret messages | 25 |
| Like computer cards | 19 |
| Like a secret missive | 21 |
| Like a secret cable | 19 |
| Like a Morse message | 20 |
| Like a heliogram | 16 |
| In secret language | 18 |
| In dots and dashes | 18 |
| Hid the meaning | 15 |
| Having secret marks, maybe | 26 |
| Hard to read, maybe | 19 |
| Encrypted, as a message | 23 |
| Enciphered | 10 |
| Emulated Hammurabi | 18 |
| Disguised the meaning | 21 |
| Did cryptography | 16 |
| Secret moniker | 14 |
| Secret identity | 15 |
| Renegade, for Barack Obama | 26 |
| Manhattan Project, e.g. | 23 |
| Spy's alias | 15 |
| Part of a cover | 15 |
| Overlord, for D-day | 19 |
| Operation Overlord, e.g. | 24 |
| Operation Desert Fox, e.g. | 26 |
| Fat Man or Abscam | 17 |
| Deep Throat, for one | 20 |
| Barack Obama's is "Renegade" | 42 |
| Alias for an agent | 18 |
| Alias for a secret agent | 24 |
| Agent's cover | 17 |
| A spy may use one | 17 |
| Early written law | 17 |
| Babylonian heritage | 19 |
| Emergency situation | 19 |
| Serious warning | 15 |
| Emergency indicator | 19 |
| Security warning | 16 |
| Official emergency status | 25 |
| Official emergency level | 24 |
| Alert status | 12 |