The need for **confidentiality, integrity, authenticity, and non-repudiation** in data transmission and data storage makes the science of cryptography one of the most important disciplines in information technology Cryptography, etymologically derived from the Greek words hidden and writing, is the process of securing data in transit or stored by third party adversaries. There are two kinds of cryptosystems: 1. [[Symmetric Cryptography]] 2. [[Asymmetric Cryptography (PKC)]] [[Symmetric Cryptography]] relies on both parties having a shared secret key that demands an exchange over a public network. [[Asymmetric Cryptography (PKC)]] was introduced to **solve the problem of key distribution in symmetric cryptography.** - [[Cryptography Types]] - [[Encryption]] - [[Perfect Secrecy]] - [[Enigma]] - [[Frequency Stability Property]] - [[Pseudorandom number generators]] - [[Quantum Key Distribution Protocols]] - [[Post Quantum Cryptography]] - [[Impact of QC on Cryptography ]] 20 billion digital devices will need to be upgraded or replaced with postquantum cryptography in the next 20 years. See: [[Homomorphic Encryption]] | [[Confidential Computing]] #security