Secret key cryptography, also known as symmetric key cryptography, is a type of encryption where a single secret key is used for both encryption and decryption of a message. The cryptographic key is kept secret between the sender and receiver, making it difficult for anyone else to decipher the message. Some of the functions of secret key cryptography are:

Key selection without integer factorization: Secret key cryptography does not rely on complex mathematical problems such as integer factorization or discrete logarithms to generate keys. Instead, the keys are chosen randomly or derived from a passphrase or a shared secret. This makes the key generation process faster and simpler than in public key cryptography.

Utilization of less memory: Secret key cryptography uses less memory than public key cryptography, as it only requires one key to be stored and managed. Public key cryptography, on the other hand, requires two keys (public and private) for each user, which increases the memory overhead and complexity of key management.

The other options are not functions of secret key cryptography, but rather characteristics of public key cryptography or asymmetric cryptography, which is a different type of encryption where different keys are used for encryption and decryption. Public key cryptography has the following features:

Utilization of different keys for encryption and decryption: Public key cryptography uses a pair of keys, one public and one private, for each user. The public key can be shared with anyone, while the private key must be kept secret. The public key is used to encrypt messages, while the private key is used to decrypt them. This allows users to communicate securely without having to exchange a secret key beforehand.

Utilization of large prime number iterations: Public key cryptography relies on hard mathematical problems such as integer factorization or discrete logarithms to generate keys. These problems involve finding the prime factors of large numbers or finding the discrete logarithms of numbers in a finite field. These problems are easy to solve in one direction, but hard to solve in the reverse direction. For example, it is easy to multiply two large prime numbers, but hard to find the prime factors of the product. This makes the keys hard to break by brute force or other methods.

Provides the capability to only know the key on one side: Public key cryptography enables users to encrypt messages without knowing the recipient’s key, and vice versa. This is possible because the encryption and decryption keys are different and mathematically related. For example, Alice can encrypt a message with Bob’s public key, and only Bob can decrypt it with his private key. Alice does not need to know Bob’s private key, and Bob does not need to know Alice’s key. This also enables public key cryptography to support digital signatures, which are a way of verifying the identity and integrity of a message.

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What Is Secret Key Cryptography? A Complete Guide - Helenix

Definition of Secret-key Cryptography - Gartner