Cryptography
Introduction to cryptography and perfect ciphers
Cryptography is the study of techniques to allow secure communication and data storage in presenc...
Computationally secure ciphers and pseudorandom number generators
A modern practical assumption is to build ciphers such that a successful attack is carried only i...
Chosen Plaintext Attacks (CPAs)
Our attacker knows a set of plaintexts which can be encrypted and he wants to understand which on...
Data integrity and Message Authentication Codes (MAC)
Confidentiality does not means integrity. Changes in the ciphertext are undetected. Message Authe...
Asymmetric cryptosystems
We would like to have the following features: Agreeing on a short secret over a public channel C...
Data authentication and digital signatures
We’d like to be able to verify the authenticity of a piece of data without a pre-shared secret. U...
The public key binding problem and digital certificates
Both in asymmetric encryption and digital signatures, the public key must be bound to the correct...
Fundamentals of Information Theory
Shannon’s information theory is a way to quantify information and to mathematically frame communi...
Exercises on cryptography
More exercises aviable at overthewire.org. 2021-2022 DEMO Exam exercise 2 (5 points) You have...