Data Cryptographic Algorithm

A Data Cryptographic Algorithm that is a data transformation algorithm that that encrypts plaintext and/or decrypts ciphertext.

• AKA: Data Encryption-Decryption Algorithm.
• Context:
  • It can be implemented by a Data Cryptographic System to solve a Data Cryptographic Task.
  • It can range from being a Data Encryption Algorithm to being a Data Decryption Algorithm.
  • It can range from being a Hash Function Algorithm, to being a Secret Key Cryptography (SKC) Algorithm, to being a Public Key Cryptography (PKC) Algorithm.
• Example(s):
  • a Public Key Cryptography (PKC) Algorithm such as:
    • a Digital Signature Algorithm,
    • an Elliptic Curve Cryptography (ECC) Algorithm,
    • a Key Exchange Algorithm (KEA),
    • …
  • a Secret Key Cryptography (SKC) Algorithm such as:
    • an International Data Encryption Algorithm (IDEA),
    • a Blowfish Cipher Algorithm,
    • a Camellia Cipher Algorithm,
    • a Serpent Cipher Algorithm,
    • …
  • a Hash Function Encryption Algorithm such as:
    • Message Digest (MD) Algorithm,
    • Secure Hash Algorithm (SHA),
    • …
• Counter-Example(s):
  • Crypto-Shredding Algorithm,
  • Database Caching Algorithm,
  • Disk Encryption Algorithm.
• See: SSH, Public Key Infrastructure (PKI), Cryptosystem, Cold Boot Attack, Cyberspace Electronic Security Act, Geoblocking, Data Erasure, Information Security, Hash Function, Decentralized Online Social Network, Authentication Server, Authentication Protocol, Public Key Certificate.

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References

2021a

• (Kessler, 2021) ⇒ Gary C. Kessler (2021)."2. Basic Concepts Of Cryptography". In: "An Overview of Cryptography".
  • QUOTE: There are five primary functions of cryptography:
    • 1.Privacy/confidentiality: Ensuring that no one can read the message except the intended receiver.
    • 2. Authentication: The process of proving one's identity.
    • 3. Integrity: Assuring the receiver that the received message has not been altered in any way from the original.
    • 4. Non-repudiation: A mechanism to prove that the sender really sent this message.
    • 5. Key exchange: The method by which crypto keys are shared between sender and receiver.

In cryptography, we start with the unencrypted data, referred to as plaintext. Plaintext is encrypted into ciphertext, which will in turn (usually) be decrypted back into usable plaintext. The encryption and decryption is based upon the type of cryptography scheme being employed and some form of key. For those who like formulas, this process is sometimes written as:

$C = E_k(P)$

$P = D_k(C)$

where $P$ = plaintext, $C$ = ciphertext, $E$ = the encryption method, $D$ = the decryption method, and $k$ = the key.

2021b

• (Kessler, 2021) ⇒ Gary C. Kessler (2021)."3. Types Of Cryptographic Algorithms". In: "An Overview of Cryptography".
  • QUOTE: There are several ways of classifying cryptographic algorithms. For purposes of this paper, they will be categorized based on the number of keys that are employed for encryption and decryption, and further defined by their application and use. The three types of algorithms that will be discussed are (Figure 1):
  • Secret Key Cryptography (SKC): Uses a single key for both encryption and decryption; also called symmetric encryption. Primarily used for privacy and confidentiality.
  • Public Key Cryptography (PKC): Uses one key for encryption and another for decryption; also called asymmetric encryption. Primarily used for authentication, non-repudiation, and key exchange.
  • Hash Functions: Uses a mathematical transformation to irreversibly "encrypt" information, providing a digital fingerprint. Primarily used for message integrity.

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

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