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Introduction to Cryptanalysis

This course introduces you to the field of cryptanalysis.

8 videos  //  37 minutes of training

Course description

Cryptographic algorithms, if used correctly, can render data impervious to attack. However, it is common for them to be used incorrectly. This course describes some of the obfuscation methods commonly used instead of strong cryptography and how to identify and break them to read the original data.

Course syllabus

Course IntroductionDuration: 1:07

This video introduces the Introduction to Cryptanalysis course.

Introduction to CryptanalysisDuration: 7:56

This video lays the groundwork for performing cryptanalysis for cybersecurity.

Entropy CalculationsDuration: 3:03

This video describes entropy calculations and their use for analyzing ciphertexts.

Character Frequency AnalysisDuration: 5:26

This video describes character frequency analysis and its use for breaking substitution ciphers.

Encryption vs EncodingDuration: 7:32

This video discusses the difference between encryption and encoding algorithms.

Breaking ROT CiphersDuration: 3:50

This video describes how to identify and break rotational ciphers.

Breaking Weak XOR EncryptionDuration: 4:03

This video describes how to identify and break improper use of XOR ciphers.

Breaking Misused Stream CiphersDuration: 3:37

This video describes how to break misused stream ciphers.

Meet the author

Howard Poston


Howard Poston is a cybersecurity researcher with a background in blockchain, cryptography and malware analysis. He has a master's degree in Cyber Operations from the Air Force Institute of Technology and two years of experience in cybersecurity research and development at Sandia National Labs.

He currently works as a freelance consultant providing training and content creation for cyber and blockchain security. He can be reached by email at or via his website at

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Plans and pricing





$599 / license

Annually. Includes all content plus team admin and reporting.