Secret Key Cryptography (SKC) Algorithm

AKA: Symmetric Encryption Algorithm.
Context:
- It can be implemented by a Secret Key Cryptography (SKC) System to solve Secret Key Cryptography (SKC) Task.
- It can range from being a Stream Cipher Algorithm to being a Block Cipher Algorithm.
Example(s):
- a Blowfish Cipher Algorithm,
- a Camellia Cipher Algorithm,
- a Data Encryption Standard (DES) Algorithm,
- a Salsa20 Encryption Algorithm,
- a Serpent Cipher Algorithm,
- …
Counter-Example(s):
- a Public Key Cryptography (PKC) Algorithm,
- a Hash Function Encryption Algorithm.
See: SSH, Data Transformation Algorithm, Public Key Infrastructure (PKI), Cryptosystem, Cold Boot Attack, Cyberspace Electronic Security Act, Geoblocking, Data Erasure, Information Security, Hash Function, Decentralized Online Social Network.

References

(Kessler, 2021) ⇒ Gary C. Kessler (2021)."3.1. Secret Key Cryptography". In: "An Overview of Cryptography".
- QUOTE: Secret key cryptography methods employ a single key for both encryption and decryption. As shown in Figure 1A, the sender uses the key to encrypt the plaintext and sends the ciphertext to the receiver. The receiver applies the same key to decrypt the message and recover the plaintext. Because a single key is used for both functions, secret key cryptography is also called symmetric encryption.
  With this form of cryptography, it is obvious that the key must be known to both the sender and the receiver; that, in fact, is the secret. The biggest difficulty with this approach, of course, is the distribution of the key (more on that later in the discussion of public key cryptography). Secret key cryptography schemes are generally categorized as being either stream ciphers or block ciphers.

**Figure 1:** Three types of cryptography: secret key, public key, and hash function.