A 5-Minute Refresher To Cryptography
Cyber Defense Magazine, Thursday, April 4th, 2024
It's an age-old question. Alice wants to send a message to Bob. But how can Alice send it to Bob without Eve, the snoopy eavesdropper, looking into their conversations or perhaps even tampering with them? Cryptography is the answer, and in this article we'll have a quick refresher on how cryptography underpins the virtual world.
Cryptography was and is everywhere - in history and in the present. What began as Caesar Cipher evolved into the Vigenere Cipher, and now includes Public-Key Cryptography and more.
Cryptography techniques can be broken down into two: symmetric and asymmetric algorithms. Cryptography plays a role in all aspects of our digital life, from the password hashing and salts used to sign into accounts, the HTTPS and TLS/SSL encryption used on websites while we surf online, the encryption and decryption associated with openPGP and S/MIME while we check our emails, or even end-to-end encryption when sending text messages. Our main goals involve confidentiality, integrity, and authenticity (the 'A' here is different from CIA Triad).
Confidentiality would mean that only the people who are supposed to be reading your message can read it, whereas integrity of the message indicates that the message hasn't been tampered with. Authenticity, on the other hand, is the notion that the sender of the message shown to the recipient isn't different from the original sender.