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.

 56 Challenges

Results Name Validations Number of points  Explanation for the scores Difficulty  Difficulty Author Note  Notation Solution Date
pas_valide Encoding - ASCII 26% 63422 5 Xartrick 10 4 December 2012
pas_valide Encoding - UU 21% 49195 5 g0uZ 10 7 October 2006
pas_valide Hash - DCC 1% 1451 5 Shutdown 1 13 July 2021
pas_valide Hash - DCC2 1% 1450 5 Shutdown 1 13 July 2021
pas_valide Hash - LM 1% 1735 5 Shutdown 1 13 July 2021
pas_valide Hash - Message Digest 5 20% 47646 5 g0uZ 7 31 January 2010
pas_valide Hash - NT 1% 1201 5 Shutdown 1 13 July 2021
pas_valide Hash - SHA-2 11% 24517 5 koma 4 3 June 2012
pas_valide Shift cipher 7% 15158 10 m31z0nyx 9 16 February 2011
pas_valide CISCO - Salted Password 1% 1049 10 Tidusrose 3 13 July 2021
pas_valide Pixel Madness 5% 11900 15 Ryscrow 10 3 February 2011
pas_valide ELF64 - PID encryption 3% 6062 15 Lu33Y 10 8 February 2012
pas_valide File - PKZIP 4% 9004 15 g0uZ 6 30 August 2010
pas_valide Monoalphabetic substitution - Caesar 5% 11469 15 Arod 5 22 October 2011
pas_valide Known plaintext - XOR 3% 6691 20 Ryscrow 5 3 February 2011
pas_valide Code - Pseudo Random Number Generator 2% 2605 20 Tosh 6 19 December 2012
pas_valide File - Insecure storage 1 3% 6886 20 g0uZ 7 6 February 2012
pas_valide Polyalphabetic substitution - Vigenère 4% 7520 20 Arod 3 26 October 2011
pas_valide System - Android lock pattern 3% 5006 20 Silentd 5 23 December 2012
pas_valide Transposition - Rail Fence 2% 4627 20 YellowS4 4 6 April 2014
pas_valide AES - CBC - Bit-Flipping Attack 1% 973 25 Tie21 4 17 June 2018
pas_valide AES - ECB 1% 1874 25 cez40 4 29 November 2015
pas_valide LFSR - Known plaintext 1% 626 25 Brissouille 2 28 November 2017
pas_valide RSA - Factorisation 2% 3253 25 HacKSpider 5 12 September 2010
pas_valide RSA - Decipher Oracle 1% 1166 25 Zweisamkeit 3 11 May 2017
pas_valide Service - Timing attack 1% 2083 25 g0uZ 4 28 October 2012
pas_valide Monoalphabetic substitution - Polybe 2% 2713 25 koma 6 6 December 2011
pas_valide Twisted secret 1% 231 25 NonStandardModel 1 14 August 2020
pas_valide Initialisation Vector 1% 1479 25 manticore 6 25 August 2015
pas_valide GEDEFU 1% 460 30 makhno 1 13 September 2016
pas_valide OTP - Implementation error 1% 159 30 Podalirius 2 22 March 2021
pas_valide RSA - Corrupted key 1 1% 289 30 blackndoor 2 28 November 2017
pas_valide RSA - Continued fractions 1% 1059 30 sambecks 1 8 September 2015
pas_valide RSA - Common modulus 1% 1216 30 franb 2 24 December 2016
pas_valide Service - Hash length extension attack 1% 757 30 koma 1 19 August 2015
pas_valide AES - 4 Rounds 1% 202 35 Cryptanalyse 0 5 September 2018
pas_valide ECDSA - Introduction 1% 190 35 Jrmbt 2 22 September 2019
pas_valide RSA - Padding 1% 205 35 Tosh 0 9 October 2016
pas_valide RSA - Signature 1% 103 35 sar 1 9 March 2020
pas_valide AES128 - CTR 1% 531 40 Tosh 2 28 August 2015
pas_valide Discrete logarithm problem 1% 805 40 RFC4949 3 8 June 2014
pas_valide RSA - Corrupted key 2 1% 194 40 blackndoor 1 11 January 2018
pas_valide RSA - Corrupted key 3 1% 100 40 blackndoor 0 5 September 2019
pas_valide RSA - Multiple recipients 1% 996 40 franb 3 29 November 2015
pas_valide AES - Fault attack #1 1% 109 50 Cryptanalyse 1 20 September 2018
pas_valide Enigma Machine 1% 184 50 peyman 2 12 October 2016
pas_valide ECDHE 1% 181 60 Tosh 2 20 November 2016
pas_valide RSA - Lee cooper 1% 92 60 blackndoor 1 7 November 2019
pas_valide Service - CBC Padding 1% 933 60 koma 1 4 October 2012
pas_valide Polyalphabetic substitution - One Time Pad 1% 328 60 Thanat0s 0 2 June 2013
pas_valide White-Box Cryptography 1% 149 60 Cryptanalyse 3 21 October 2018
pas_valide AES - Weaker variant 1% 93 70 Cryptanalyse 1 29 August 2018
pas_valide Hash - SHA-3 1% 116 75 Revenger 1 10 December 2016
pas_valide AES - Fault attack #2 1% 80 80 Cryptanalyse 1 20 September 2018
pas_valide AES-PMAC 1% 17 100 Cryptanalyse 0 26 May 2019
pas_valide ECDSA - Implementation error 1% 34 100 Tosh 0 29 September 2019

Challenge Results Challenge Results

Pseudo Challenge Lang Date
Ashiya   Encodage - UU 22 January 2022 at 20:02
Ashiya   Encodage - ASCII 22 January 2022 at 20:00
ibra99   Encodage - UU 22 January 2022 at 19:58
Guigui   Vecteur d’initialisation 22 January 2022 at 19:48
marwan1205   Encodage - ASCII 22 January 2022 at 19:43
RootCAM   Système - Android lock pattern 22 January 2022 at 19:05
Alane Jaunet   Encodage - ASCII 22 January 2022 at 19:03
Guigui   Twisted secret 22 January 2022 at 19:01
fff_flu   Hash - SHA-2 22 January 2022 at 19:00
Lucaïstos   Hash - Message Digest 5 22 January 2022 at 18:36