What is Cryptography?
Cryptography is the study of enciphering and deciphering information preserving the privacy of enciphered information.
Modern cryptography is mathematically robust and plays a critical role in securing sensitive information like your bank account numbers and social security number. While the mathematics may seem complex and intimidating, the concepts are graspable even without completely understanding the encryption algorithms.
Cryptography is made up of a collection of primitives which serve as building blocks for different cryptographic protocols. Some examples of cryptogrpahic primitives include hash functions such as sha-256 and md5(a one way map), and verifiable random functions (VRFs). True randomness is extremely difficult to capture, but mathematicians have developed a way to construct randomness that is indistinguishable from true randomness.
These primitives are used to build more robust tools like ciphers. Ciphers are algorithms used to conceal (encrypt) and decrypt information. The encrypted data is called ciphertext, while the translated information is called plaintext. There are two general categories of ciphers, symmetric ciphers and asymmetric ciphers. We will go into the difference and some examples throughout this section.