Cryptography

This resource covers the theoretical and practical foundations of cryptography, with emphasis on how SSL/TLS use cryptographic tools to secure data over the Internet. Key cryptographic tools discussed include symmetric encryption, asymmetric encryption, and hashing. The topics covered also include how these cryptographic tools can help secure data and authenticate clients/servers.

How SSL/TLS use cryptography (series)

Hashing algorithms and message integrity – Part 1 (December 15, 2023)

This post explains the key qualities of a hashing algorithm. The post also explains how hashing algorithms can be used to ensure the integrity of messages exchanged between a client/sender and server/receiver.

Confidentiality and cryptographic encryption – Part 2 (December 18, 2023)

This post explains how symmetric encryption and asymmetric encryption can be used to protect the privacy of data (confidentiality).

Using asymmetric keys – Part 3 (December 19, 2023)

This post discusses how asymmetric keys are used to perform message confidentiality and message signing. We then look at two real world applications involving the asymmetric key pair, real world encryption and real world signatures.

Authentication methods – Part 4 (December 21, 2023)

This post discusses three common methods of authentication: username and password, Pre-Shared Keys (PSKs), and digital certificates.

Replay attacks and anti-replay methods – Part 5 (December 22, 2023)

This post discusses replay attacks and anti-replay methods. Six anti-replay methods that are not mutually exclusive are covered, including using sequence numbers, using cryptographic hashes, and rotating the secret keys.

Rivest–Shamir–Adleman (RSA) example – Part 6 (December 25, 2023)

This post presents a working example of RSA’s key generation, encryption, and signing capabilities. The post covers the steps involved in generating an RSA key, and then applies the key to a plain text to see how RSA encryption works.

Special topics in cryptography

How to get started in cryptography – article highlights (July 28, 2021)

Learn about the four primary goals of cryptography, the meaning of key terms/concepts used in cryptography, and how to get started in cryptography.

How to secure your data – article highlights (July 28, 2021)

Data security can be based on the classic CIA triad: confidentiality, integrity, and availability. Here’s a summary of the steps needed to achieve those three critical objectives.

Wireless network security (May 31, 2023)

This lesson covers a lot of authentication methods and encryption and message integrity algorithms used in wireless security management.