Crypto 3: Advanced Symmetric Cryptography
by Arnav Vora
We further explore and review symmetric cryptography. We also delve into padding schemes for block ciphers and explore the padding oracle attack - an attack that uses padding to exfiltrate plaintexts! Finally, we also learn about modular arithmetic and its use in cryptography.
Slides
Challenges
The following challenges in increasing difficulty are deployed to platform.acmcyber.com to practice the concepts covered in the slides.
These challenges are review from last week that we will finish this week: (tags on the platform: crypto, cyber academy, week 4,5)
crypto/extremely-convenient-beakercrypto/convenient-cbccrypto/bigramcrypto/admin-login
Resources
The following resources are great to practice/learn about the concepts covered in the slides.
- pycryptodome: A library that implements many modern-day cryptographic algorithms.
- cryptohack: A website with many challenges related to cryptography
- Modes of Operation: A good article about the different modes of operation of block ciphers.
- Padding oracle attacks: A website/tool to visualize and learn how padding oracle attacks work