Level I Challenges
Description
The Syllabary cipher seems to be just another substitution cipher, but is it? Find out and solve its mystery! Show details…Hide details…
Author
Nils Kopal
Publication
Oct. 28, 2022, 1:24 p.m.
179 users have already solved this challenge, 31 are working on it.
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Description
The legendary Merkle-Hellman Knapsack cryptosystem is not suitable for hiking, but it is considered a pioneer of asymmetric cryptography.
Can you crack the ciphertext? Show details…Hide details…
Author
Peter Uelkes
Publication
Oct. 14, 2022, 5:22 p.m.
61 users have already solved this challenge, 11 are working on it.
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Description
This challenge is about one of the oldest polyalphabetic ciphers.
Can you crack this centuries-old puzzle? Show details…Hide details…
Author
Peter Uelkes
Publication
March 26, 2022, 8:40 p.m.
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131 users have already solved this challenge, 19 are working on it.
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Description
The Wheatstone Cryptograph is a simple device that resembles a clock with two hands. For each hand there is a ring of symbols.
Are you able to decrypt the given ciphertext? Show details…Hide details…
Author
madness
Publication
April 21, 2021, 7:17 p.m.
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102 users have already solved this challenge, 8 are working on it.
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Description
This series deals with a grid — a basic tool cryptographers use to separate sequences of data into columns and rows. In this challenge you are given three grids where the first grid gives you hints to reveal the plaintext of the second grid. Are you able to find the right route? Show details…Hide details…
Author
Viktor Veselovsky
Publication
Dec. 26, 2020, 6:24 p.m.
32 users have already solved this challenge, 5 are working on it.
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Description
This series deals with a grid — a basic tool cryptographers use to separate sequences of data into columns and rows. In this challenge you are given four grids where the first grid gives you hints to reveal the plaintext of the second grid. Are you able to find the right route? Show details…Hide details…
Author
Viktor Veselovsky
Publication
Dec. 19, 2020, 4:53 p.m.
33 users have already solved this challenge, 3 are working on it.
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Description
This series deals with a grid — a basic tool cryptographers use to separate sequences of data into columns and rows. In this challenge you are given two grids where the first grid gives you hints to reveal the plaintext of the second grid. Are you able to find the right route? Show details…Hide details…
Author
Viktor Veselovsky
Publication
Oct. 27, 2020, 5:01 p.m.
90 users have already solved this challenge, 19 are working on it.
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Description
Lattice-based cryptography schemes are relevant for current post-quantum cryptography research. This challenge series accompanies the basic theory from a chapter of the CrypTool Book called "LIGHTWEIGHT INTRODUCTION TO LATTICES". This part of the challenge series uses vectors to hide a famous quote in modern art. Can you reveal it? Show details…Hide details…
Authors
Miroslav Dimitrov,
Bernhard Esslinger
Publication
June 23, 2020, 11:05 p.m.
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40 users have already solved this challenge, 4 are working on it.
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Description
Lattice-based cryptography schemes are relevant for current post-quantum cryptography research. This challenge series accompanies the basic theory from a chapter of the CrypTool Book called "LIGHTWEIGHT INTRODUCTION TO LATTICES". In this part of the challenge series we introduce systems of linear equations to find a hidden message in a picture. Show details…Hide details…
Authors
Miroslav Dimitrov,
Bernhard Esslinger
Publication
May 16, 2020, 4:03 p.m.
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56 users have already solved this challenge, 5 are working on it.
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Description
This part of the challenge series is a warm-up with homophonic substitution. In a homophonic substitution cipher, there are more than one ciphertext symbol for each plaintext symbol. The key is a mapping. Show details…Hide details…
Author
madness
Publication
March 22, 2020, 1:57 a.m.
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53 users have already solved this challenge, 7 are working on it.
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Description
Solving this challenge is not as hard as finding the needle in a haystack, isn't it? Show details…Hide details…
Author
Joao Vaz Martins
Publication
Jan. 9, 2019, 2:10 p.m.
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203 users have already solved this challenge, 38 are working on it.
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Description
Three messages were delivered — two encrypted, one in clear. Can you solve the puzzle? Show details…Hide details…
Author
Joao Vaz Martins
Publication
Oct. 26, 2018, 8:33 p.m.
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33 users have already solved this challenge, 39 are working on it.
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Description
The autokey cipher uses only a short keyword and the plaintext to encrypt messages. Are you able to break the given ciphertext? Show details…Hide details…
Author
Chaoyun Li
Publication
Sept. 25, 2018, 2:21 p.m.
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188 users have already solved this challenge, 13 are working on it.
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Description
What do you know about modular sequences? Work it out. Show details…Hide details…
Author
Chaoyun Li
Publication
Sept. 25, 2018, 2:19 p.m.
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79 users have already solved this challenge, 36 are working on it.
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Description
How many experience points does Thomas need to reach the 200th level of his new computer game? Show details…Hide details…
Author
Benjamin Strauss
Publication
April 18, 2018, 4:56 p.m.
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118 users have already solved this challenge, 22 are working on it.
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Description
Little Anna has forgotten how to decrypt her ciphertext. Can you come up to her pre-Christmas wish? Show details…Hide details…
Author
Anna Lena Rotthaler
Publication
Dec. 8, 2017, 7:24 p.m.
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498 users have already solved this challenge, 26 are working on it.
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Description
Are you able to crack the password of Radomil and find the missing 5 digits? Show details…Hide details…
Author
Andreas Kölblin
Publication
Nov. 16, 2017, 5:43 p.m.
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120 users have already solved this challenge, 67 are working on it.
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Description
This series consists of five parts which are based on each other and that will be getting more and more complicated with each part. This part is the actual challenge and tells you the New Year's greeting of the author. Show details…Hide details…
Author
Marc Gutgesell
Publication
March 21, 2016, 10:02 a.m.
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44 users have already solved this challenge, 13 are working on it.
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Description
This series consists of five parts which are based on each other and that will be getting more and more complicated with each part. Part 4 contains a little New Year's greeting of the author and part 5 teaches us something about the weaknesses of this method. Part 3 adds another modification. Show details…Hide details…
Author
Marc Gutgesell
Publication
March 21, 2016, 9:59 a.m.
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47 users have already solved this challenge, 4 are working on it.
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Description
This series consists of five parts which are based on each other and that will be getting more and more complicated with each part. Part 4 contains a little New Year's greeting of the author and part 5 teaches us something about the weaknesses of this method. Part 2 modifies the encryption of part 1 a little bit. Show details…Hide details…
Author
Marc Gutgesell
Publication
March 21, 2016, 9:55 a.m.
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49 users have already solved this challenge, 3 are working on it.
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Description
This series consists of five parts which are based on each other and that will be getting more and more complicated with each part. Part 4 contains a little New Year's greeting of the author and part 5 teaches us something about the weaknesses of this method. Part 1 is the easiest part of this series. Show details…Hide details…
Author
Marc Gutgesell
Publication
March 21, 2016, 9:48 a.m.
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54 users have already solved this challenge, 19 are working on it.
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Description
Both images in this challenge seem to contain no information at all. Or do they trick us? Find the secret message. Show details…Hide details…
Author
Joerg Gerschuetz
Publication
Nov. 20, 2015, 8:26 p.m.
161 users have already solved this challenge, 25 are working on it.
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Description
The story of the simple bookseller Paul from Eisleben and his beloved from the near Castle Mansfeld will be continued: A second postcard has been found.
Can you decipher the encrypted message? Show details…Hide details…
Author
Joerg Gerschuetz
Publication
Nov. 13, 2015, 12:43 p.m.
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59 users have already solved this challenge, 1 is working on it.
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Description
The challenges for the simplified GRANIT cipher, a method that can be done manually, serve as an exercise and use an intentionally simplified version of GRANIT.
Part 1 is a ciphertext-only challenge for which both permutation keys are known. Show details…Hide details…
Author
Jörg Drobick
Publication
Sept. 24, 2015, 7:30 a.m.
49 users have already solved this challenge, 5 are working on it.
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Description
How are the numbers interconnected? Can you find the three missing numbers? Show details…Hide details…
Author
George Theofanidis
Publication
Sept. 14, 2015, 8:54 a.m.
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405 users have already solved this challenge, 33 are working on it.
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Description
A friend of yours has given you the following text which contains only X and Y characters. He claims that this text contains a codeword. Can you find it? Show details…Hide details…
Author
George Theofanidis
Publication
April 16, 2015, 4:47 p.m.
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113 users have already solved this challenge, 51 are working on it.
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Description
How are the numbers linked? Can you find the two missing numbers? Show details…Hide details…
Author
Bruce Kallick
Publication
March 23, 2015, 11:51 a.m.
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97 users have already solved this challenge, 37 are working on it.
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Description
How are the numbers linked? Can you find the two missing numbers? Show details…Hide details…
Author
Bruce Kallick
Publication
March 23, 2015, 11:49 a.m.
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163 users have already solved this challenge, 20 are working on it.
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Description
This is the beginner's challenge in a series about M-138, a manual cipher of the US army which has been relatively save at the beginning of world war 2nd. Part 1 of the series is a ciphertext-only challenge whose key is largely known. Show details…Hide details…
Author
K. Schmeh
Publication
Dec. 24, 2014, 12:28 a.m.
224 users have already solved this challenge, 16 are working on it.
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Description
You can find a short encrypted note at the end of the novel "Die achte Offenbarung" by Karl Olsberg. Decrypt the secret message! Show details…Hide details…
Author
Bernhard Esslinger
Publication
Sept. 22, 2014, 10:13 p.m.
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99 users have already solved this challenge, 22 are working on it.
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Description
This challenge is based on the Heartbleed bug in OpenSSL discovered in April 2014. Attack a server which is specifically prepared to be vulnerable to the Heartbleed bug. Please note that it is necessary to solve Part 1 first.
!!! We had to take off this challenge, as our firewall doesn't allow flawed servers any more -- even if this flaw was offered by will for training and within a sandbox. !!! Show details…Hide details…
Author
A. Wacker
Publication
Aug. 28, 2014, 2:34 p.m.
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60 users have already solved this challenge, 12 are working on it.
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The solution for this challenge was made public on May 17, 2022, 6:32 p.m., and thus it is no longer possible to get points for this challenge.
Description
This challenge is based on the Heartbleed Bug in OpenSSL discovered in April 2014. Attack a server provided by the group for Privacy and Compliance with the Research Institute Cyber Defence (CODE) at Bundeswehr University Munich, which is specifically prepared to be vulnerable to the Heartbleed bug.
!!! We had to take off this challenge, as our firewall doesn't allow flawed servers any more -- even if this flaw was offered by will for training and within a sandbox. !!! Show details…Hide details…
Author
A. Wacker
Publication
Aug. 28, 2014, 2:32 p.m.
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90 users have already solved this challenge, 21 are working on it.
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The solution for this challenge was made public on May 17, 2022, 6:32 p.m., and thus it is no longer possible to get points for this challenge.
Description
In this part of this series of Enigma challenges, a plaintext message consisting of three letters which are repeated several times has been encrypted by the Enigma I. What are the first three letters of the plaintext? Show details…Hide details…
Author
George Lasry
Publication
March 5, 2014, 4:04 p.m.
82 users have already solved this challenge, 9 are working on it.
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Description
In this part of this series of Enigma challenges, a plaintext message consisting of three letters which are repeated several times has been encrypted by the Enigma I. What was the setting of the Enigma rotors? Show details…Hide details…
Author
George Lasry
Publication
March 5, 2014, 4:03 p.m.
78 users have already solved this challenge, 3 are working on it.
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Description
In this part of this series of Enigma challenges, a plaintext message consisting of two letters which are repeated several times has been encrypted by the Enigma I. What was the setting of the Enigma rotors? Show details…Hide details…
Author
George Lasry
Publication
March 5, 2014, 4:02 p.m.
86 users have already solved this challenge, 3 are working on it.
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Description
In this part of this series of Enigma challenges, a plaintext message consisting of one letter which is repeated several times has been encrypted by the Enigma I. What was the setting of the Enigma rotors? Show details…Hide details…
Author
George Lasry
Publication
Oct. 28, 2013, 8:53 p.m.
86 users have already solved this challenge, 17 are working on it.
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Description
Two scatterbrained professors exchange messages that have been encrypted with the Trifid cipher. Unfortunately, one of them lost the second of three layers. Will he nevertheless be able to decrypt the message he received from his colleague? Show details…Hide details…
Author
Sansibar
Publication
Oct. 28, 2013, 8:49 p.m.
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128 users have already solved this challenge, 8 are working on it.
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Description
In this part of this series of Enigma challenges, a plaintext message consisting of one letter which is repeated several times has been encrypted by the Enigma I. What is the letter we are looking for? Show details…Hide details…
Author
George Lasry
Publication
Sept. 26, 2013, 3:05 p.m.
179 users have already solved this challenge, 35 are working on it.
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Description
You find a note with strange characters and an unsolved Sudoku on your brother's desk. You are curious and would like to find out what your brother is working on. Can you decrypt the note using the Sudoku? Show details…Hide details…
Author
Emmanouil Doulgerakis
Publication
Sept. 4, 2013, 4:27 p.m.
107 users have already solved this challenge, 5 are working on it.
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Description
Sarah and Igor are exchange students. Sarah lives in Moscow while Igor is in Berlin. To keep their little secrets confidential, they encrypt their emails. Decrypt the message to find out what Sarah wrote this time. Show details…Hide details…
Author
Sansibar
Publication
Sept. 4, 2013, 2:30 p.m.
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293 users have already solved this challenge, 33 are working on it.
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Description
Nils would like to go on a journey and has given you a note with information about his destination. The note is encrypted. Can you find out where he would like to go? Show details…Hide details…
Authors
Nils Griese,
Nathalie Hänig
Publication
Aug. 8, 2013, 1 p.m.
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175 users have already solved this challenge, 15 are working on it.
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Description
The seven dwarfs are missing. Snow White however finds a file, which contains useful information steganographically hidden. Help her to find the dwarfs. Show details…Hide details…
Author
Lena Meier
Publication
April 20, 2013, 11:23 a.m.
295 users have already solved this challenge, 86 are working on it.
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Description
The reserve hand procedure has been used as a replacement of the Enigma machine. Can you decrypt the given ciphertext? Show details…Hide details…
Author
Michael Hörenberg
Publication
March 6, 2013, 9:14 p.m.
195 users have already solved this challenge, 11 are working on it.
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Description
The plaintext consists of English, French, German and Italian words. Can you identify the four sentences after you have solved the monoalphabetic substitution? Show details…Hide details…
Author
George Theofanidis
Publication
Jan. 30, 2013, 2:27 p.m.
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79 users have already solved this challenge, 6 are working on it.
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Description
Can you break this cascading encryption that consists of a combination of substitution and transposition? The solution contains important information for the next parts. Show details…Hide details…
Author
A. Wacker
Publication
Jan. 25, 2013, 3 p.m.
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73 users have already solved this challenge, 2 are working on it.
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Description
Can you find the plaintext using 26 Engima ciphertexts that have been encrypted with different rotors and different initial settings? Show details…Hide details…
Author
George Theofanidis
Publication
Jan. 23, 2013, 3:32 p.m.
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82 users have already solved this challenge, 4 are working on it.
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Description
In this challenge, only fragments of the grid used for a Playfair encryption are given. Are you able to reconstruct the matrix and decrypt the message? Show details…Hide details…
Author
George Theofanidis
Publication
Jan. 16, 2013, noon
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119 users have already solved this challenge, 6 are working on it.
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Description
This PDF file is supposed to contain a hidden codeword. Can you find it? Show details…Hide details…
Author
George Theofanidis
Publication
Jan. 6, 2013, 2:32 p.m.
858 users have already solved this challenge, 165 are working on it.
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Description
This postcard from Thessaloniki was written in German in 1897. The encrypted text can either be considered as message from the sailor Fritz to his wife at home, or as a note regarding spionage activities. Can you determine the codeword that was used to request secret information? Show details…Hide details…
Author
T. Schroedel
Publication
Dec. 10, 2012, 3:10 p.m.
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51 users have already solved this challenge, 5 are working on it.
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Description
Can you decrypt the three military messages? Show details…Hide details…
Author
George Ho
Publication
Nov. 20, 2012, 4:48 p.m.
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69 users have already solved this challenge, 13 are working on it.
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Description
The Beaver Code is a transposition cipher. Apart from the solution of this challenge, can you find a formula for any given ciphertext length, which generates the permutation needed to decrypt the ciphertext? Show details…Hide details…
Author
Lena Meier
Publication
Aug. 13, 2012, 8:12 p.m.
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1214 users have already solved this challenge, 45 are working on it.
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Description
Can you decrypt the second part of the letter to the Templars as effortlessly as the first one? Show details…Hide details…
Author
Bernhard Esslinger
Publication
July 30, 2012, 8:10 p.m.
839 users have already solved this challenge, 12 are working on it.
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Description
After the Order of the Templar has become very powerful, enviers try to crush it. The knights receive an encrypted letter but the key does not arrive. Does this letter contain the warning that would have saved the knights from being arrested? Show details…Hide details…
Author
Bernhard Esslinger
Publication
July 16, 2012, 9:08 p.m.
1044 users have already solved this challenge, 43 are working on it.
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Description
Your friend sent you an audio file that contains only a strange melody. In the email, your friend writes that the file contains a message encoded by a variant of Morse code. Can you find out how you can hear the Morse code? Show details…Hide details…
Author
Viktor Veselovsky
Publication
June 5, 2012, 7:56 p.m.
41 users have already solved this challenge, 19 are working on it.
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Description
You are invited to a job interview for the job of a cryptographer. Can you pass the first selection round? Show details…Hide details…
Author
Viktor Veselovsky
Publication
May 28, 2012, 5:07 p.m.
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230 users have already solved this challenge, 106 are working on it.
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Description
How are the numbers linked? Can you find the three missing numbers? Show details…Hide details…
Author
River Edis-Smith
Publication
April 18, 2012, 7:27 p.m.
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104 users have already solved this challenge, 130 are working on it.
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Description
Can you find the link between these numbers? Show details…Hide details…
Author
River Edis-Smith
Publication
April 18, 2012, 7:25 p.m.
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849 users have already solved this challenge, 23 are working on it.
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Description
You don't speak Spanish? No Problem!
Try to decrypt a ciphertext in a foreign language without knowledge of that language. Show details…Hide details…
Author
Bart den Hartog
Publication
April 18, 2012, 7:19 p.m.
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168 users have already solved this challenge, 18 are working on it.
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Description
This number sequence is cyclic. Can you find out the fifth and sixth number? Show details…Hide details…
Author
River Edis-Smith
Publication
March 30, 2012, 10:49 p.m.
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1027 users have already solved this challenge, 109 are working on it.
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Description
In order to decrypt the intercepted letter addressed to your neighbor, you need to find out which document has been used to encode the message with the book code. Show details…Hide details…
Author
Lena Meier
Publication
March 21, 2012, 11:02 a.m.
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153 users have already solved this challenge, 27 are working on it.
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Description
Alice and Bob would like to agree upon a shared key. They use an Elliptic Curve Diffie-Hellman (ECDH) key-exchange protocol. Try to reproduce the steps that are necessary to calculate the key and to decrypt Bob's message. Show details…Hide details…
Author
Lena Meier
Publication
Feb. 24, 2012, midnight
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100 users have already solved this challenge, 2 are working on it.
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Description
Alice and Bob use the cipher as it had been described in part 3 of this challenge. Due to an error one message has been encrypted and sent twice. Does this help you to find out the shared key and enables you to decrypt a third message easily? Show details…Hide details…
Author
Viktor Veselovsky
Publication
Dec. 21, 2011, 1:50 p.m.
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51 users have already solved this challenge, 5 are working on it.
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Description
It is not difficult to break a monoalphabetic substitution but in this challenge an additional camouflage alphabet causes confusion. Show details…Hide details…
Author
Viktor Veselovsky
Publication
Oct. 27, 2011, 9:40 a.m.
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66 users have already solved this challenge, 8 are working on it.
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Description
With the help of 7 pairs of plaintext-ciphertext you have to find out how this factorization cipher works and then decrypt a ciphertext. Show details…Hide details…
Author
Viktor Veselovsky
Publication
Oct. 17, 2011, 6:42 p.m.
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512 users have already solved this challenge, 17 are working on it.
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Description
You intercepted two ENIGMA I messages. Both are dated from the same day. Use a Turing Bombe to find out the key of the day and decipher the solution. Show details…Hide details…
Author
Michael Hörenberg
Publication
Oct. 17, 2011, 6:36 p.m.
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73 users have already solved this challenge, 3 are working on it.
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Description
A friend of yours sent you a file that seems to be empty. Was it just a mistake or is there a secret to reveal? Show details…Hide details…
Author
Viktor Veselovsky
Publication
Oct. 17, 2011, 6:25 p.m.
61 users have already solved this challenge, 18 are working on it.
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Description
You need to reconstruct some fields of the grille to decrypt the message written on an old note. Show details…Hide details…
Author
Lena Meier
Publication
Oct. 14, 2011, 6 p.m.
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499 users have already solved this challenge, 41 are working on it.
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Description
Asterix and Obelix besiege Rome. They just happened to find an encrypted message but instead of the common Caesar Cipher the Romans used a new method. Can you decrypt the message? Show details…Hide details…
Author
Dano
Publication
Oct. 12, 2011, 2:03 p.m.
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118 users have already solved this challenge, 4 are working on it.
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Description
Two girls want to communicate in a secret way using the „affine cipher“. Transform the encryption rule into the decryption rule and turn in the plaintext of the example. Show details…Hide details…
Authors
Tanja Lange,
Andreas Grüner,
Bernhard Esslinger
Publication
Sept. 9, 2011, 11:24 a.m.
602 users have already solved this challenge, 11 are working on it.
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Description
In this challenge the rotational relationship between the Pigpen symbols are used to create a new cipher. In this part the well-known key squares are used as a warm up. Show details…Hide details…
Author
Daniel Fretwell
Publication
Sept. 5, 2011, 10:17 p.m.
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156 users have already solved this challenge, 7 are working on it.
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Description
The Caesar Chiper is rather simple. But in this challenge it is used with a different alphabet and a modified way of shifting the letters. Show details…Hide details…
Author
Viktor Veselovsky
Publication
Sept. 2, 2011, 1:02 p.m.
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233 users have already solved this challenge, 61 are working on it.
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Description
A pair of plaintext and the corresponding ciphertext encrypted with the ADFGVX cipher ist given. Can you reveal the substitution and transposition key used in this example? Show details…Hide details…
Author
Volker Simon
Publication
Aug. 15, 2011, 5:14 p.m.
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126 users have already solved this challenge, 8 are working on it.
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Description
A small ciphertext encrypted with the ADFGVX cipher, which has been used during World War I, is given. Are you able to reveal the plaintext message? Show details…Hide details…
Author
Volker Simon
Publication
Aug. 15, 2011, 5:11 p.m.
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121 users have already solved this challenge, 17 are working on it.
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Description
This sequence is infinite, the first 9 numbers are given. What are the 10th and 11th number? Show details…Hide details…
Author
Bernhard Esslinger
Publication
July 11, 2011, 2:34 p.m.
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2143 users have already solved this challenge, 486 are working on it.
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Description
A piece of music is given as mp3 file and in music notation. The notes represent a secret message, which was encrypted with two classic methods. In part 1 of this challenge you have to solve the first of these methods. Thereafter, you can set out to solve part 2 (which is in level 2). Show details…Hide details…
Author
Henning Wolter
Publication
May 17, 2011, 10 a.m.
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43 users have already solved this challenge, 30 are working on it.
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Description
By the time quantum computers exist, the actual signing algorithms are not secure anymore. Then one can switch e.g. to so-called "Unbalanced Oil and Vinegar" systems. It is your challenge to break a simplified version of such a system today already. Show details…Hide details…
Authors
Marc Kleffmann,
Enrico Thomae,
Christopher Wolf
Publication
April 7, 2011, midnight
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100 users have already solved this challenge, 2 are working on it.
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Description
A friend sends you a cipher designed by him and asks you to discover the used key, using a given plaintext and the corresponding ciphertext. Show details…Hide details…
Author
Bernhard Esslinger
Publication
March 4, 2011, midnight
107 users have already solved this challenge, 7 are working on it.
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Description
In this challenge you shall break the Playfair encryption which was used by the British forces in the Crimean War and in World War I, among others. Show details…Hide details…
Author
Pascal Schöttle
Publication
Dec. 22, 2010, midnight
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128 users have already solved this challenge, 11 are working on it.
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Description
In this challenge you shall break the Caesar encryption in its original form. Show details…Hide details…
Author
Bernhard Esslinger
Publication
Dec. 15, 2010, midnight
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3069 users have already solved this challenge, 146 are working on it.
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Description
The Enigma is an electro-mechanical rotor machine used for encryption and decryption. One main part of the Enigma is changeable rotors. This challenge deals with the calculation of the key space. Show details…Hide details…
Author
Bernhard Esslinger
Publication
Nov. 12, 2010, 3:31 p.m.
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107 users have already solved this challenge, 65 are working on it.
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Description
The "Three Investigators" heard that it was possible to create truly unbreakable cipher texts if you linked a stream of true random numbers to the plaintext (one-time pad). However this random stream must be incalculable for outsiders. Do you think you can, nevertheless, decrypt an eavesdropped encrypted message from the "Three Investigators"? Show details…Hide details…
Author
Bernhard Esslinger
Publication
Nov. 12, 2010, 3:30 p.m.
315 users have already solved this challenge, 23 are working on it.
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Description
This is part 2 of a 3-part challenge regarding the classical transposition. You can solve this challenge with pen and paper as well as with different software programs. To create the ciphertext the plaintext was first encrypted with a classical shift cipher. The result of this encryption was then further encrypted with a columnar transposition with a key length of less than 10 characters. Show details…Hide details…
Author
A. Wacker
Publication
Oct. 23, 2010, 3 p.m.
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150 users have already solved this challenge, 7 are working on it.
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Description
This is part 1 of a 3-part challenge regarding the classical transposition. You can solve this challenge with pen and paper as well as with adequate software programs (e.g. CrypTool 2). With this irregular columnar tranposition a key length greater than 10 was used. Show details…Hide details…
Author
A. Wacker
Publication
Oct. 23, 2010, 10 a.m.
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159 users have already solved this challenge, 11 are working on it.
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Description
Homophonic substitution using 5 ciphertext characters for a binary cleartext alphabet. This challenge can be solved with paper & pencil. Show details…Hide details…
Author
Bernhard Esslinger
Publication
Oct. 21, 2010, 7:51 p.m.
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343 users have already solved this challenge, 8 are working on it.
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Description
Homophonic substitution using 3 ciphertext characters for a binary cleartext alphabet. This challenge can be solved with paper & pencil. Show details…Hide details…
Author
Bernhard Esslinger
Publication
Oct. 21, 2010, 7:50 p.m.
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398 users have already solved this challenge, 76 are working on it.
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Description
The Caesar encryption, a very simple example of a monoalphabetic substitution. Show details…Hide details…
Author
Bernhard Esslinger
Publication
Oct. 21, 2010, 7:49 p.m.
1467 users have already solved this challenge, 790 are working on it.
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Description
In the late 1960s the so called Zodiac killer used a homophonic substitution encryption to encrypt letters to the police and the press. This challenge is inspired by the solved Zodiac-408 problem and the unsolved Zodiac-340 problem.
Hint: Provide the codeword in capital letters. Show details…Hide details…
Author
Mark Stamp
Publication
Oct. 14, 2010, 1:30 p.m.
101 users have already solved this challenge, 39 are working on it.
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Description
This is a famous speech of a German soccer star - including a mistake. The codeword consists of 2 words, one after the other with no space. The first is the password used to encrypt the plaintext, and the second is the mistake in the decrypted text. (The plaintext is in German.) Show details…Hide details…
Author
Bernhard Esslinger
Publication
Oct. 14, 2010, 1:30 p.m.
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556 users have already solved this challenge, 184 are working on it.
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Description
This sequence is infinite, but you may recognize it after just 13 numbers. What is the 14th number?
Please type in the numeric expression of the number. Show details…Hide details…
Author
Bernhard Esslinger
Publication
Oct. 14, 2010, 1:30 p.m.
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4353 users have already solved this challenge, 429 are working on it.
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Description
In 1806, the young countess Julie finds a dress with an old enciphered letter in a pouch. It reveals a secret of one of Julie's ancestors. Can you break the cipher?
The codeword for this challenge is the last word of the letter (all uppercase). Show details…Hide details…
Author
T. Schroedel
Publication
Oct. 14, 2010, 1:30 p.m.
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181 users have already solved this challenge, 20 are working on it.
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Description
In September 1902, a book seller named Paul Winkler received a postcard in cipher. Sent from the nearby Mansfeld castle, it appears that a young lady wants to meet with Paul – secretly.
Find the name of the young lady and submit it as the codeword for this challenge. Use only capital letters. Show details…Hide details…
Author
T. Schroedel
Publication
Oct. 14, 2010, 1:30 p.m.
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131 users have already solved this challenge, 19 are working on it.
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Description
This challenge contains three messages encrypted with classical ciphers. You will need break each of the ciphers and take note of the three codewords. When you have all three codewords, submit them in the form "codeword1-codeword2-codeword3". Please note that the codewords are case sensitive and you have only 5 trials to find the correct solution.
The MTC3 team wishes everybody much success and fun in finding the correct solution. Show details…Hide details…
Author
A. Wacker
Publication
Oct. 14, 2010, 1:30 p.m.
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188 users have already solved this challenge, 17 are working on it.
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