Cryptanalysis Cryptanalysis

Break encryption algorithms

These tests will allow you to hone your cryptography skills. You will be faced with an encoded data. The challenge is to find the type of encoding or encryption and revert it back to find the solution.

Prerequisites:

– Knowledge of most common encoding formats.
– Knowledge of most common hash algorithms and ciphers.
– Knowledge of a scripting language.

challenges 75 Challenges

Results Name Validations ↓↑ Number of points  Explanation for the scores Difficulty  Difficulty Author Note  Notation Solution Date
pas_valide Goldreich Goldwasser Halevi | Weak Parameter 1% 45 50 Vozec 0 13 December 2024
pas_valide NTRU | Weak Parameter 1% 47 60 Vozec 0 13 December 2024
pas_valide NTRU | Multiple Transmission 1% 51 60 Vozec 0 13 December 2024
pas_valide AES-PMAC 1% 58 100 Cryptanalyse 0 26 May 2019
pas_valide FEAL - Differential Cryptanalysis 1% 61 50 Tosh 1 28 March 2022
pas_valide Shamir Secret Sharing - Irreducible ? 1% 63 90 Mister7F 1 5 February 2024
pas_valide Shamir Secret Sharing - Reduction 1% 87 70 Vozec 0 5 February 2024
pas_valide ECDSA - Implementation error 1% 91 100 Tosh 0 29 September 2019
pas_valide ElGamal - Fault attack (Introduction) 1% 93 35 Vozec 0 13 December 2024
pas_valide RSA - H-rabin 1% 114 60 Vozec 0 21 March 2023
pas_valide Side Channel - AES : CPA 1% 130 50 cb34 0 28 March 2022
pas_valide Side Channel - AES : first round 1% 137 60 walafc0 0 28 March 2022
pas_valide Shamir Secret Sharing - Traitor 1% 142 35 Vozec 1 5 February 2024
pas_valide AES - Fault attack #2 1% 165 80 Cryptanalyse 1 20 September 2018
pas_valide DSA - Implementation error 1% 175 25 Vozec 1 13 December 2024
pas_valide AES - Weaker variant 1% 188 70 Cryptanalyse 1 29 August 2018
pas_valide RSA - Lee cooper 1% 189 60 blackndoor , Synacktiv 1 7 November 2019
pas_valide PHP - mt_rand 1% 198 40 NonStandardModel 0 28 March 2022
pas_valide Hash - SHA-3 1% 218 75 Revenger 1 10 December 2016
pas_valide RSA - Corrupted key 3 1% 219 40 blackndoor 0 5 September 2019
pas_valide AES - Fault attack #1 1% 236 50 Cryptanalyse 1 20 September 2018
pas_valide RSA - Signature 1% 254 35 sar 1 9 March 2020
pas_valide ECDHE 1% 275 60 Tosh 2 20 November 2016
pas_valide Enigma Machine 1% 292 50 peyman 2 12 October 2016
pas_valide White-Box Cryptography 1% 302 60 Cryptanalyse 3 21 October 2018
pas_valide RSA - Padding 1% 324 35 Tosh 0 9 October 2016
pas_valide Hill Cipher 1% 325 30 LetMeR00t 1 21 March 2023
pas_valide RSA - Corrupted key 2 1% 359 40 blackndoor 1 11 January 2018
pas_valide ECDSA - Introduction 1% 399 35 Jrmbt 2 22 September 2019
pas_valide AES - 4 Rounds 1% 410 35 Cryptanalyse 0 5 September 2018
pas_valide Polyalphabetic substitution - One Time Pad 1% 429 60 Thanat0s 0 2 June 2013
pas_valide AES - ECB - Copy Paste 1% 436 25 Vozec 1 5 February 2024
pas_valide Shamir Secret Sharing - Introduction 1% 455 30 Vozec 2 5 February 2024
pas_valide RSA - Corrupted key 1 1% 499 30 blackndoor 2 28 November 2017
pas_valide File - PKZIP 2 1% 529 20 kevin.mille 2 8 November 2024
pas_valide OTP - Implementation error 1% 562 30 Podalirius 3 22 March 2021
pas_valide Encoding - Codebook 1% 570 20 n3rada 1 21 March 2023
pas_valide Twisted secret 1% 604 25 NonStandardModel 2 14 August 2020
pas_valide GEDEFU 1% 608 30 makhno 1 13 September 2016
pas_valide AES128 - CTR 1% 812 40 Tosh 2 28 August 2015
pas_valide LFSR - Known plaintext 1% 1237 25 Brissouille 2 28 November 2017
pas_valide Service - Hash length extension attack 1% 1256 30 koma 1 19 August 2015
pas_valide Discrete logarithm problem 1% 1423 40 RFC4949 3 8 June 2014
pas_valide Service - CBC Padding 1% 1454 60 koma 2 4 October 2012
pas_valide RSA - Continued fractions 1% 1651 30 sambecks 1 8 September 2015
pas_valide RSA - Multiple recipients 1% 1753 40 franb 4 29 November 2015
pas_valide AES - CBC - Bit-Flipping Attack 1% 1771 25 Tie21 5 17 June 2018
pas_valide Circular Bit Shift 1% 2125 20 BlackRaven 3 21 March 2023
pas_valide RSA - Common modulus 1% 2214 30 franb 3 24 December 2016
pas_valide RSA - Decipher Oracle 1% 2227 25 Zweisamkeit 4 11 May 2017
pas_valide Initialisation Vector 1% 2432 25 manticore , notfound404 6 25 August 2015
pas_valide AES - ECB 1% 2915 25 cez40 4 29 November 2015
pas_valide Service - Timing attack 1% 3044 25 g0uZ , koma 5 28 October 2012
pas_valide Code - Pseudo Random Number Generator 2% 3990 20 Tosh 6 19 December 2012
pas_valide Monoalphabetic substitution - Polybe 2% 4152 25 koma 6 6 December 2011
pas_valide RSA - Factorisation 2% 5447 25 HacKSpider 5 12 September 2010
pas_valide CISCO - Salted Password 2% 6287 10 Tidusrose 3 13 July 2021
pas_valide Transposition - Rail Fence 2% 6917 20 YellowS4 4 6 April 2014
pas_valide System - Android lock pattern 2% 7302 20 Silentd 5 23 December 2012
pas_valide Hash - NT 3% 7774 5 Podalirius 2 13 July 2021
pas_valide ELF64 - PID encryption 3% 8537 15 Lu33Y 10 8 February 2012
pas_valide Hash - DCC2 3% 9105 5 Podalirius 1 13 July 2021
pas_valide Hash - LM 3% 9564 5 Podalirius 2 13 July 2021
pas_valide File - Insecure storage 1 3% 9730 20 g0uZ 7 6 February 2012
pas_valide Known plaintext - XOR 3% 9902 20 Ryscrow 5 3 February 2011
pas_valide Hash - DCC 3% 9988 5 Podalirius 1 13 July 2021
pas_valide Polyalphabetic substitution - Vigenère 3% 11074 20 Arod 3 26 October 2011
pas_valide File - PKZIP 4% 14088 15 g0uZ 6 30 August 2010
pas_valide Pixel Madness 5% 17112 15 Ryscrow 10 3 February 2011
pas_valide Monoalphabetic substitution - Caesar 5% 17927 15 Arod 5 22 October 2011
pas_valide Shift cipher 6% 22140 10 m31z0nyx 10 16 February 2011
pas_valide Hash - SHA-2 9% 33985 5 koma 4 3 June 2012
pas_valide Hash - Message Digest 5 17% 64234 5 g0uZ 7 31 January 2010
pas_valide Encoding - UU 20% 74456 5 g0uZ 10 7 October 2006
pas_valide Encoding - ASCII 26% 97120 5 Xartrick 10 4 December 2012

Challenge Results Challenge Results

Pseudo Challenge Lang Date
fulanke Cryptanalyse  Encodage - UU fr 16 February 2026 at 15:32
fulanke Cryptanalyse  Encodage - ASCII fr 16 February 2026 at 15:31
bigmushfrog23 Cryptanalyse  Substitution monoalphabétique - Polybe fr 16 February 2026 at 15:29
NeoNeTech Cryptanalyse  CISCO - Salted Password fr 16 February 2026 at 15:28
IamAurel Cryptanalyse  Clair connu - XOR fr 16 February 2026 at 15:18
NeoNeTech Cryptanalyse  Circular Bit Shift fr 16 February 2026 at 15:04
RootBJJ Cryptanalyse  Encodage - ASCII fr 16 February 2026 at 15:02
Ret2Skillz Cryptanalyse  Shamir Secret Sharing - Traitor fr 16 February 2026 at 15:02
IamAurel Cryptanalyse  Circular Bit Shift fr 16 February 2026 at 15:01
freepalestiinee Cryptanalyse  Hash - SHA-3 fr 16 February 2026 at 14:58