Cryptography
Cryptography is the study and practice of keeping information secret. It is used in information security to maintain the confidentiality and integrity of data as well as to enable non-repudiation. It allows for secure communication of information from unauthorized parties. In our look at cryptography, we will be examining encryption and cryptographic hash functions, which are tools that can be used to secure data.
Encryption
Encryption is the process of transforming ordinary data, which is referred to as plaintext, into a format that is unreadable, which is referred to as ciphertext. This prevents unauthorized parties from accessing it. Data is encrypted using an encryption algorithm in conjunction with an encryption key. Larger key sizes result in greater encryption strength but make the process of encryption/decryption slower.
Data that is encrypted can be reverted to its original value. Encryption is used over hashing when there is a need to know the decrypted value. For example...
