Cryptography
Learning outcomes:
- Explain the difference between symmetric and asymmetric encryption
- Describe how public and private keys, hashes, and digital signatures are used
- Encrypt stored data using a tool such as VeraCrypt
- Describe legal issues around encryption, such as backdoors and key disclosure laws
Would you like to download my PowerPoint to follow along?
- What is encryption?
- Encryption and decryption
- Who cares? Anyone who stores or sends private information
- Symmetric and asymmetric encryption
- Computer encryption history
- Enigma machines
- DES (Data Encryption Standard)
- Released 1977
- Triple DES
- Publicly broken in 1999
- AES (Advanced Encryption Standard)
- Published 2001
- Approved for NSA classified data in 2003
- Cryptanalysis
- How much information is known: ciphertext only, known plaintext, or chosen plaintext
- Frequency analysis
- The love story of Alice and Bob
- Public and private keys: what happens if the private key is lost?
- Digital signatures
- One way functions and hash functions
- xkcd: Alice and Bob
- Encrypting stored data
- Mobile data
- Cloud data
- Backups
- Password control and management
- Encrypting communications
- Chat
- Timed encryptions
- Blockchain
- A continuously growing list of records
- Blocks linked and secured using cryptography
- An example of distributed computing, such as Bitcoin
- Legal issues
- Backdoors and golden keys
- The US used to treat encryption as a weapon for export, under the International Traffic in Arms Regulations
- Key disclosure laws, such as In re Boucher
Suggested Activities and Discussion Topics:
- In class activity: use VeraCrypt to create a 20 MB encrypted container, mount it, add some files, and dismount it. What does the container look like in File Explorer when it's dismounted?
- Discussion: should governments have a backdoor into encryption? Who benefits, and who is put at risk?
- Hands-on practice: try the free TryHackMe rooms Cryptography for Dummies and Crack the Hash. They run in safe practice environments built for learning, with a free account.
- Hands-on practice: try the Cryptography and General Skills challenges in picoCTF, a free practice platform from Carnegie Mellon University, now part of the CyLab Security Academy.
- Password cracking: follow the instructions on this PDF (accessible HTML version)
- Security video review: follow the instructions on this PDF (accessible HTML version)
Would you like to see some more classes? View all classes