# Cryptography – SHA Secure Hash Algorithm, SHA 256

# Cryptography explained:

Cryptography is the practice and study of techniques for secure communication. When A sends data to B it should not be intervened by a third party C so that it becomes a secure communication. Cryptography is about constructing and analyzing protocols that prevent third parties or the public from reading private messages;various aspects in information security such as data confidentiality, data integrity, authentication, and non-repudiation are central to modern cryptography. Modern cryptography exists at the intersection of the disciplines of** mathematics, computer science, electrical engineering, and communication science.** Applications of cryptography are so many that include email, eCcommerce, debit/credit payment cards, digital currencies, computer passwords, and military communications.

## Encryption explained:

Cryptography is almost taken for granted now as encryption, which is the process of converting ordinary information into unintelligible text. For example in Chainscripts is ordinary text and 00000660da1cb9d07f99b3bc4578c7f8466a7e1 is unintelligible text. Quite natural that there is a decryption process converting the unintelligible text to plain text! Well a key is needed to do this. In a simple symmetric system, same key is used to encrypt and decrypt. In asymmetric system, a public key is used to encrypt a message and a private key to decrypt it. There are several asymmetric Crypto techniques available.

## SHA explained:

Secure Hash Algorithm is a set of Cryptographic hash functions designed by the United States National Security Agency or NSA. The SHA-2 family consists of six hash functions with digests that are 224, 256, 384 or 512 bits: SHA-224, SHA-256, SHA-384, SHA-512, SHA-512/224, SHA-512/256. SHA-256 and SHA-512 are novel hash functions computed with 32-bit and 64-bit words, respectively. In the example Chainscripts (input) to 00000660da1cb9d07f99b3bc4578c7f8466a7e1 (output hash value) a mathematical algorithmic approach is adopted to get the output for the input. Cryptography and hash functions are the main pillars of Blockchain technology.

Malick, Chain Scripts, Chennai, India.

‘I have no special talent. I am only passionately curious’. -Albert Einstein