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 ECDSA - Implementation error 1% 69 100 Tosh 0 29 September 2019
pas_valide Side Channel - AES : first round 1% 94 60 walafc0 0 28 March 2022
pas_valide FEAL - Differential Cryptanalysis 1% 51 50 Tosh 0 28 March 2022
pas_valide Goldreich Goldwasser Halevi | Weak Parameter 1% 21 50 Vozec 0 13 December 2024
pas_valide Side Channel - AES : CPA 1% 91 50 cb34 0 28 March 2022
pas_valide PHP - mt_rand 1% 176 40 NonStandardModel 0 28 March 2022
pas_valide NTRU | Multiple Transmission 1% 29 60 Vozec 0 13 December 2024
pas_valide NTRU | Weak Parameter 1% 21 60 Vozec 0 13 December 2024
pas_valide RSA - H-rabin 1% 91 60 Vozec 0 21 March 2023
pas_valide RSA - Corrupted key 3 1% 197 40 blackndoor 0 5 September 2019
pas_valide RSA - Padding 1% 298 35 Tosh 0 9 October 2016
pas_valide Polyalphabetic substitution - One Time Pad 1% 386 60 Thanat0s 0 2 June 2013
pas_valide ElGamal - Fault attack (Introduction) 1% 38 35 Vozec 0 13 December 2024
pas_valide Shamir Secret Sharing - Reduction 1% 51 70 Vozec 0 5 February 2024
pas_valide Shamir Secret Sharing - Irreducible ? 1% 35 90 Mister7F 0 5 February 2024
pas_valide AES-PMAC 1% 40 100 Cryptanalyse 0 26 May 2019
pas_valide AES - 4 Rounds 1% 367 35 Cryptanalyse 0 5 September 2018
pas_valide RSA - Signature 1% 212 35 sar 1 9 March 2020
pas_valide Hill Cipher 1% 230 30 LetMeR00t 1 21 March 2023
pas_valide GEDEFU 1% 581 30 makhno 1 13 September 2016
pas_valide Shamir Secret Sharing - Traitor 1% 104 35 Vozec 1 5 February 2024
pas_valide RSA - Corrupted key 2 1% 333 40 blackndoor 1 11 January 2018
pas_valide RSA - Continued fractions 1% 1522 30 sambecks 1 8 September 2015
pas_valide DSA - Implementation error 1% 73 25 Vozec 1 13 December 2024
pas_valide Shamir Secret Sharing - Introduction 1% 362 30 Vozec 1 5 February 2024
pas_valide AES - ECB - Copy Paste 1% 347 25 Vozec 1 5 February 2024
pas_valide AES - Fault attack #1 1% 205 50 Cryptanalyse 1 20 September 2018
pas_valide Service - Hash length extension attack 1% 1194 30 koma 1 19 August 2015
pas_valide Encoding - Codebook 1% 454 20 n3rada 1 21 March 2023
pas_valide RSA - Lee cooper 1% 170 60 blackndoor , Synacktiv 1 7 November 2019
pas_valide AES - Weaker variant 1% 151 70 Cryptanalyse 1 29 August 2018
pas_valide Hash - SHA-3 1% 164 75 Revenger 1 10 December 2016
pas_valide AES - Fault attack #2 1% 147 80 Cryptanalyse 1 20 September 2018
pas_valide Hash - DCC2 3% 8139 5 Podalirius 1 13 July 2021
pas_valide Hash - DCC 3% 8857 5 Podalirius 1 13 July 2021
pas_valide ECDHE 1% 246 60 Tosh 2 20 November 2016
pas_valide AES128 - CTR 1% 738 40 Tosh 2 28 August 2015
pas_valide Service - CBC Padding 1% 1384 60 koma 2 4 October 2012
pas_valide ECDSA - Introduction 1% 342 35 Jrmbt 2 22 September 2019
pas_valide Enigma Machine 1% 276 50 peyman 2 12 October 2016
pas_valide RSA - Corrupted key 1 1% 457 30 blackndoor 2 28 November 2017
pas_valide LFSR - Known plaintext 1% 1094 25 Brissouille 2 28 November 2017
pas_valide Hash - NT 2% 6944 5 Podalirius 2 13 July 2021
pas_valide Twisted secret 1% 529 25 NonStandardModel 2 14 August 2020
pas_valide File - PKZIP 2 1% 346 20 kevin.mille 2 8 November 2024
pas_valide Hash - LM 3% 8603 5 Podalirius 2 13 July 2021
pas_valide RSA - Common modulus 1% 2080 30 franb 3 24 December 2016
pas_valide White-Box Cryptography 1% 254 60 Cryptanalyse 3 21 October 2018
pas_valide Circular Bit Shift 1% 1751 20 BlackRaven 3 21 March 2023
pas_valide Polyalphabetic substitution - Vigenère 3% 10655 20 Arod 3 26 October 2011
pas_valide CISCO - Salted Password 2% 5616 10 Tidusrose 3 13 July 2021
pas_valide Discrete logarithm problem 1% 1334 40 RFC4949 3 8 June 2014
pas_valide OTP - Implementation error 1% 487 30 Podalirius 3 22 March 2021
pas_valide RSA - Decipher Oracle 1% 2094 25 Zweisamkeit 4 11 May 2017
pas_valide AES - ECB 1% 2761 25 cez40 4 29 November 2015
pas_valide Transposition - Rail Fence 2% 6661 20 YellowS4 4 6 April 2014
pas_valide Hash - SHA-2 9% 32932 5 koma 4 3 June 2012
pas_valide RSA - Multiple recipients 1% 1665 40 franb 4 29 November 2015
pas_valide System - Android lock pattern 2% 7073 20 Silentd 5 23 December 2012
pas_valide RSA - Factorisation 2% 5118 25 HacKSpider 5 12 September 2010
pas_valide Service - Timing attack 1% 2943 25 g0uZ , koma 5 28 October 2012
pas_valide AES - CBC - Bit-Flipping Attack 1% 1693 25 Tie21 5 17 June 2018
pas_valide Known plaintext - XOR 3% 9486 20 Ryscrow 5 3 February 2011
pas_valide Monoalphabetic substitution - Caesar 5% 16967 15 Arod 5 22 October 2011
pas_valide Monoalphabetic substitution - Polybe 2% 3997 25 koma 6 6 December 2011
pas_valide File - PKZIP 4% 13461 15 g0uZ 6 30 August 2010
pas_valide Initialisation Vector 1% 2307 25 manticore , notfound404 6 25 August 2015
pas_valide Code - Pseudo Random Number Generator 2% 3724 20 Tosh 6 19 December 2012
pas_valide Hash - Message Digest 5 17% 62326 5 g0uZ 7 31 January 2010
pas_valide File - Insecure storage 1 3% 9455 20 g0uZ 7 6 February 2012
pas_valide Shift cipher 6% 21180 10 m31z0nyx 10 16 February 2011
pas_valide Pixel Madness 5% 16439 15 Ryscrow 10 3 February 2011
pas_valide ELF64 - PID encryption 3% 8183 15 Lu33Y 10 8 February 2012
pas_valide Encoding - UU 20% 71431 5 g0uZ 10 7 October 2006
pas_valide Encoding - ASCII 26% 92831 5 Xartrick 10 4 December 2012

Challenge Results Challenge Results

Pseudo Challenge Lang Date
mohamed ghodbane Cryptanalysis  Hash - DCC en 25 July 2025 at 23:12
m1n3ll Cryptanalyse  Hash - Message Digest 5 fr 25 July 2025 at 23:12
m1n3ll Cryptanalyse  Hash - LM fr 25 July 2025 at 23:11
n1ghtp4rliament Cryptanalysis  Encoding - ASCII es 25 July 2025 at 22:40
corslyn Cryptanalyse  Service - Timing attack fr 25 July 2025 at 22:39
Yojhan Cryptanalysis  Encoding - ASCII es 25 July 2025 at 22:28
Konix Cryptanalyse  Hash - Message Digest 5 fr 25 July 2025 at 22:17
Konix Cryptanalyse  Hash - LM fr 25 July 2025 at 22:14
Konix Cryptanalyse  Hash - DCC2 fr 25 July 2025 at 22:05
mohamed ghodbane Cryptanalysis  Encoding - ASCII en 25 July 2025 at 22:04