A DAY OF CRYPTOGRAPHY AND RANDOMNESS - 49.900 kr (taught in english)

(Before Noon)

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BREAKING HISTORICAL CIPHERS

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The use of encryption for the protection of communication during war time is of critical importance – and has been for thousands of years. In the 19th century, the United States was embroiled in a Civil War with both the South (the Confederacy) using a well-known and classical encryption method (of Italian and French origin) and the North (the Union) using a new approach.

 

In this talk, we consider several historical ciphers – and then we look at two previously undeciphered examples from the US Civil War – and we break them. 

 

LEARNING OUTCOMES:

 

• Understand the fundamentals of both monoalphabetic and polyalphabetic ciphers.

• Understand the differences between ciphers and codes.

• Being able to identify and exploit weaknesses in both monoalphabetic and polyalphabetic ciphers.

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(After Noon)

MEASUREMENTS OF UNCERTAINTY AND THE GOOD, THE BAD AND THE UGLY OF RANDOMNESS

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In the world of Computer Science, information is a measure of not what you do know but, rather, what you don’t know. The higher the information content, the entropy, the more random the data (or the outcome of an experiment, or a variable). And random is often very desirable for many applications, especially in cryptography. And not random (low entropy) can be very bad.

 

We’ll experiment and measure uncertainty and entropy in language, in games and, of course, in the music of Justin Bieber.

 

And this will lead us to fundamentals of passwords and data storage and data security. And then we’ll look at United States (formerly CLASSIFIED) efforts and successes breaking unbreakable Soviet secret messages of the 1940’s and 1950’s - and the unmasking of spies.

 

LEARNING OUTCOMES:

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• Understand the meaning of the entropy of a random variable - and being able to calculate examples of entropies in data and in music and in language.

• Understand passwords and cryptographic keys for symmetric encryption (especially password-based encryption) – and the impact entropy has on both.

• Learn about and experiment with a few different efficient data encodings. And understand data storage through compression - with one application to cryptanalysis.