metalnem / cryptopals

Erlang solutions to the Matasano Crypto Challenges

Matasano Crypto Challenges

Erlang solutions to the Matasano Crypto Challenges (http://cryptopals.com/). Solutions to the remaining challenges are written in Go and can be found here.

Set 1: Basics

1. Convert hex to base64 (problem, solution)
2. Fixed XOR (problem, solution)
3. Single-byte XOR cipher (problem, solution)
4. Detect single-character XOR (problem, solution)
5. Implement repeating-key XOR (problem, solution)
6. Break repeating-key XOR (problem, solution)
7. AES in ECB mode (problem, solution)
8. Detect AES in ECB mode (problem, solution)

Set 2: Block crypto

9. Implement PKCS#7 padding (problem, solution)
10. Implement CBC mode (problem, solution)
11. An ECB/CBC detection oracle (problem, solution)
12. Byte-at-a-time ECB decryption (Simple) (problem, solution)
13. ECB cut-and-paste (problem, solution)
14. Byte-at-a-time ECB decryption (Harder) (problem, solution)
15. PKCS#7 padding validation (problem, solution)
16. CBC bitflipping attacks (problem, solution)

Set 3: Block & stream crypto

17. The CBC padding oracle (problem, solution)
18. Implement CTR, the stream cipher mode (problem, solution)
19. Break fixed-nonce CTR mode using substitions (problem, solution)
20. Break fixed-nonce CTR statistically (problem, solution)
21. Implement the MT19937 Mersenne Twister RNG (problem, solution)
22. Crack an MT19937 seed (problem, solution)
23. Clone an MT19937 RNG from its output (problem, solution)
24. Create the MT19937 stream cipher and break it (problem, solution)

Set 4: Stream crypto and randomness

25. Break "random access read/write" AES CTR (problem, solution)
26. CTR bitflipping (problem, solution)
27. Recover the key from CBC with IV=Key (problem, solution)
28. Implement a SHA-1 keyed MAC (problem, solution)
29. Break a SHA-1 keyed MAC using length extension (problem, solution)