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 Hash - Message Digest 5 17% 63437 5 g0uZ 7 31 January 2010
pas_valide Encoding - UU 20% 73385 5 g0uZ 10 7 October 2006
pas_valide File - PKZIP 4% 13766 15 g0uZ 6 30 August 2010
pas_valide File - Insecure storage 1 3% 9636 20 g0uZ 7 6 February 2012
pas_valide Known plaintext - XOR 3% 9760 20 Ryscrow 5 3 February 2011
pas_valide Pixel Madness 5% 16818 15 Ryscrow 10 3 February 2011
pas_valide RSA - Factorisation 2% 5269 25 HacKSpider 5 12 September 2010
pas_valide ELF64 - PID encryption 3% 8388 15 Lu33Y 10 8 February 2012
pas_valide ECDSA - Implementation error 1% 72 100 Tosh 0 29 September 2019
pas_valide ECDHE 1% 260 60 Tosh 2 20 November 2016
pas_valide FEAL - Differential Cryptanalysis 1% 53 50 Tosh 1 28 March 2022
pas_valide AES128 - CTR 1% 783 40 Tosh 2 28 August 2015
pas_valide RSA - Padding 1% 309 35 Tosh 0 9 October 2016
pas_valide Code - Pseudo Random Number Generator 2% 3893 20 Tosh 6 19 December 2012
pas_valide Shift cipher 6% 21754 10 m31z0nyx 10 16 February 2011
pas_valide Encoding - ASCII 26% 95613 5 Xartrick 10 4 December 2012
pas_valide GEDEFU 1% 591 30 makhno 1 13 September 2016
pas_valide Monoalphabetic substitution - Caesar 5% 17509 15 Arod 5 22 October 2011
pas_valide Polyalphabetic substitution - Vigenère 3% 10902 20 Arod 3 26 October 2011
pas_valide Side Channel - AES : first round 1% 111 60 walafc0 0 28 March 2022
pas_valide Polyalphabetic substitution - One Time Pad 1% 413 60 Thanat0s 0 2 June 2013
pas_valide Monoalphabetic substitution - Polybe 2% 4090 25 koma 6 6 December 2011
pas_valide Service - Hash length extension attack 1% 1223 30 koma 1 19 August 2015
pas_valide Service - CBC Padding 1% 1426 60 koma 2 4 October 2012
pas_valide Hash - SHA-2 9% 33549 5 koma 4 3 June 2012
pas_valide System - Android lock pattern 2% 7229 20 Silentd 5 23 December 2012
pas_valide RSA - Continued fractions 1% 1581 30 sambecks 1 8 September 2015
pas_valide AES - ECB 1% 2862 25 cez40 4 29 November 2015
pas_valide Transposition - Rail Fence 2% 6826 20 YellowS4 4 6 April 2014
pas_valide AES - CBC - Bit-Flipping Attack 1% 1740 25 Tie21 5 17 June 2018
pas_valide LFSR - Known plaintext 1% 1181 25 Brissouille 2 28 November 2017
pas_valide Discrete logarithm problem 1% 1386 40 RFC4949 3 8 June 2014
pas_valide Enigma Machine 1% 285 50 peyman 2 12 October 2016
pas_valide RSA - Corrupted key 3 1% 204 40 blackndoor 0 5 September 2019
pas_valide RSA - Corrupted key 2 1% 345 40 blackndoor 1 11 January 2018
pas_valide RSA - Corrupted key 1 1% 472 30 blackndoor 2 28 November 2017
pas_valide RSA - Common modulus 1% 2162 30 franb 3 24 December 2016
pas_valide RSA - Multiple recipients 1% 1712 40 franb 4 29 November 2015
pas_valide Hill Cipher 1% 286 30 LetMeR00t 1 21 March 2023
pas_valide RSA - Signature 1% 233 35 sar 1 9 March 2020
pas_valide RSA - Decipher Oracle 1% 2170 25 Zweisamkeit 4 11 May 2017
pas_valide Hash - SHA-3 1% 194 75 Revenger 1 10 December 2016
pas_valide ECDSA - Introduction 1% 368 35 Jrmbt 2 22 September 2019
pas_valide Shamir Secret Sharing - Irreducible ? 1% 46 90 Mister7F 1 5 February 2024
pas_valide Hash - DCC2 3% 8747 5 Podalirius 1 13 July 2021
pas_valide Hash - DCC 3% 9574 5 Podalirius 1 13 July 2021
pas_valide Hash - LM 3% 9190 5 Podalirius 2 13 July 2021
pas_valide Hash - NT 2% 7435 5 Podalirius 2 13 July 2021
pas_valide OTP - Implementation error 1% 533 30 Podalirius 3 22 March 2021
pas_valide AES-PMAC 1% 44 100 Cryptanalyse 0 26 May 2019
pas_valide AES - Fault attack #2 1% 157 80 Cryptanalyse 1 20 September 2018
pas_valide AES - 4 Rounds 1% 393 35 Cryptanalyse 0 5 September 2018
pas_valide AES - Fault attack #1 1% 223 50 Cryptanalyse 1 20 September 2018
pas_valide AES - Weaker variant 1% 167 70 Cryptanalyse 1 29 August 2018
pas_valide White-Box Cryptography 1% 279 60 Cryptanalyse 3 21 October 2018
pas_valide Side Channel - AES : CPA 1% 109 50 cb34 0 28 March 2022
pas_valide Twisted secret 1% 573 25 NonStandardModel 2 14 August 2020
pas_valide PHP - mt_rand 1% 189 40 NonStandardModel 0 28 March 2022
pas_valide CISCO - Salted Password 2% 6034 10 Tidusrose 3 13 July 2021
pas_valide Shamir Secret Sharing - Traitor 1% 123 35 Vozec 1 5 February 2024
pas_valide AES - ECB - Copy Paste 1% 398 25 Vozec 1 5 February 2024
pas_valide Shamir Secret Sharing - Reduction 1% 65 70 Vozec 0 5 February 2024
pas_valide DSA - Implementation error 1% 142 25 Vozec 1 13 December 2024
pas_valide NTRU | Weak Parameter 1% 32 60 Vozec 0 13 December 2024
pas_valide RSA - H-rabin 1% 98 60 Vozec 0 21 March 2023
pas_valide NTRU | Multiple Transmission 1% 39 60 Vozec 0 13 December 2024
pas_valide Goldreich Goldwasser Halevi | Weak Parameter 1% 33 50 Vozec 0 13 December 2024
pas_valide Shamir Secret Sharing - Introduction 1% 420 30 Vozec 2 5 February 2024
pas_valide ElGamal - Fault attack (Introduction) 1% 69 35 Vozec 0 13 December 2024
pas_valide Circular Bit Shift 1% 2001 20 BlackRaven 3 21 March 2023
pas_valide Encoding - Codebook 1% 529 20 n3rada 1 21 March 2023
pas_valide File - PKZIP 2 1% 447 20 kevin.mille 2 8 November 2024
pas_valide Service - Timing attack 1% 2998 25 g0uZ , koma 5 28 October 2012
pas_valide Initialisation Vector 1% 2386 25 manticore , notfound404 6 25 August 2015
pas_valide RSA - Lee cooper 1% 177 60 blackndoor , Synacktiv 1 7 November 2019

Challenge Results Challenge Results

Pseudo Challenge Lang Date
Tom.H Cryptanalysis  AES - ECB en 7 December 2025 at 16:51
Rauf Cryptanalysis  Monoalphabetic substitution - Caesar en 7 December 2025 at 16:47
charly_azerty Cryptanalyse  CISCO - Salted Password fr 7 December 2025 at 16:46
Tom.H Cryptanalysis  AES - CBC - Bit-Flipping Attack en 7 December 2025 at 16:40
nono_974 Cryptanalyse  Chiffrement par décalage fr 7 December 2025 at 16:28
nono_974 Cryptanalyse  Substitution monoalphabétique - César fr 7 December 2025 at 16:19
nono_974 Cryptanalyse  Hash - NT fr 7 December 2025 at 16:15
jade Cryptanalyse  Encodage - ASCII fr 7 December 2025 at 16:03
Tracid56 Cryptanalyse  Hash - DCC fr 7 December 2025 at 15:38
Tracid56 Cryptanalyse  Chiffrement par décalage fr 7 December 2025 at 15:35