Tech and Education

What is Cryptography ? Cryptography is about constructing and analyzing protocols that prevent third parties or the public from reading private messages . Various aspects of information security such as data confidentiality, data integrity, authentication, and non-repudiation are central to modern cryptography. Prior to the modern age, cryptography was effectively synonymous with encryption , the conversion of information from a readable state to apparent nonsense. Modern cryptography is heavily based on mathematical theory and computer science. Cryptographic algorithms are designed around computational hardness assumptions, making the algorithms hard for adversaries to break. There exist information-theoretically secure schemes that probably cannot be broken even with unlimited computing power.   Cryptography also plays a major role in digital rights management and copyright infringement of digital media. Caesar Cipher The Caesar Cipher is one of the earliest known and simplest...

Plain text - a clear text message. Encryption - the process of turning a clear-text message (plaintext) into a data stream which looks like a meaningless and random sequence of bits (ciphertext). Decryption - the process of getting plaintext from encrypted data. Cipher - a cryptographic algorithm that uses a mathematical functions which takes plaintext as the input and produces ciphertext as the output and vice versa. Key - a  cryptographic key is a string of bits used by a cryptographic algorithm to transform plain text into cipher text or vice versa. Stream ciphers - symmetric algorithms that operate on 1 bit (or sometimes 1 byte) of plaintext at a time. Block ciphers - algorithms that operate on blocks of bits at a time. Symmetric algorithms - algorithms that we the same key for encryption and decryption. Public-Key (Asymmetric) algorithms - algorithms that use two different keys (public and private) for encryption and decryption. ! The first use of the term cryptograp...