Cryptography

Written by Steve Miller

Introduction

Cryptography is the practice and design of tools to secure communications in the presence of potential adversaries. Cryptographic transmissions are encrypted to ensure the security of a message while in transit across public communication channels such as the Internet. Encrypting the data makes it inaccessible to unauthorized recipients.

To keep the data inaccessible to those who shouldn’t have it, while still maintaining access for those that should, most forms of Cryptography rely on keys to encrypt and decrypt messages.

Three common encryption models are:

Private Key Cryptography (SKC): Single key used to Encrypt and Decrypt communications.

Symmetric encryption model.

Public Key Cryptography (PKC): Separate keys for encrypting and decrypting communications. Asymmetric encryption model.

Hash Functions: Mathematical transformation of communications to encrypt them. Creating a digital fingerprint of the communications content.

Using keys ensures only the sender and authorized recipient of a communication are able to view it.

Hash functions do not rely on keys. Instead, a fixed-length hash value is calculated that cannot be reversed engineered to its source, verifying the contents of a communication have not been tampered with.

Suggested Reading

Cryptography for Cryptocurrency by Louis Lapat

Explaining the Crypto in Cryptocurrency by Shobhit Seth