33 Decode the Dreaded Alphabet Cypher™️ 2019-11-29T12:47:38.897

20 Decrypt xor-encryption 2017-06-02T17:39:28.427

18 Implement the Enigma Machine 2016-02-08T21:24:10.120

18 Codebreakers and Codewriters 2017-07-19T18:12:43.117

17 Simple encryption for people on a byte budget 2017-06-14T00:23:21.263

16 Golfing end-to-end encryption 2017-04-09T20:03:58.280

13 Implement this key cipher 2016-08-19T13:39:28.793

12 Let's Encrypt It! 2018-02-08T00:59:36.533

11 Russian Caesar cipher 2019-10-10T06:57:39.030

8 Secret Message Part 1, Elements 2017-07-23T19:29:02.687

4 Straddling Checkerboard Cipher 2017-05-30T18:21:37.317

3 Keyboard Encryption 2017-03-19T02:42:43.940

-1 Encrypting and Decrypting Challenge 2016-05-02T12:20:37.493