Cryptography - The Basics
What is Cryptography?
Cryptography is a technique of securing information from unintended observers which is done by a crucial principle of cryptography called encryption.
Encryption is a process of converting information into an incomprehensible format in order to maintain confidentiality.
What are Ciphers?
These are also called encryption algorithms or systems used for encrypting and decrypting the data. A ciphers takes the plaintext or information and convert it into ciphertext using a secret key.
Ciphers are classified into two types based on how it works:
- Block Ciphers
- Stream Ciphers
Cipher algorithms are categorised into three different categories based on the key used :
- Symmetric Key Cipher - Key used to encrypt information will be the same as the key used to decrypt information.
- Asymmetric Key Cipher - Key used to encrypt differs from the key used to decrypt information.
- Hash Functions - There is no usage of any key in this algorithm. A hash value with a fixed length is calculated as per the plain text which makes it impossible for the contents of plain text to be recovered