Cryptographic Algorithm

A Cryptographic Algorithm is a data processing algorithm that can be implemented by a cryptographic system to solve a cryptographic task (that encrypts plaintext and/or decrypts ciphertext).

• AKA: Data Encryption-Decryption Algorithm.
• Context:
  • It can (typically) evolve to adapt to the increasing Computational Power and Cryptanalytic Techniques.
  • It can (often) utilize Mathematical Functions and Computational Algorithms with known computational complexity properties.
  • It can (often) be subject to Cryptanalysis for evaluating its Security Strength.
  • It can be used to ensure Data Confidentiality, Data Integrity, Authentication, and Non-Repudiation.
  • 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.
  • It can be critical for Secure Communication in various Critical Applications like Internet Security, Banking Systems, and Secure Communication Networks.
  • It can range from being a Symmetric-Key Cryptography to being a Asymmetric-Key Cryptography.
  • ...
• Example(s):
  • a Public Key Cryptography (PKC) Algorithm such as:
    • RSA Algorithm, an asymmetric algorithm used for secure data transmission.
    • Elliptic Curve Cryptography (ECC) Algorithm, providing security with smaller key sizes.
    • Digital Signature Algorithm,
    • Key Exchange Algorithm (KEA),
    • …
  • a Secret Key Cryptography (SKC) Algorithm such as:
    • Advanced Encryption Standard (AES), a symmetric algorithm used in various security protocols.
    • International Data Encryption Algorithm (IDEA),
    • Blowfish Cipher Algorithm,
    • Camellia Cipher Algorithm,
    • Serpent Cipher Algorithm,
    • Blowfish, a symmetric block cipher known for its speed and effectiveness.
    • …
  • a Hash Function Encryption Algorithm such as:
    • Message Digest (MD) Algorithm,
    • Secure Hash Algorithm (SHA),
    • SHA-256, a cryptographic hash function used for data integrity checks.
    • …
  • …
• Counter-Example(s):
  • A Crypto-Shredding Algorithm.
  • A Database Caching Algorithm.
  • A Disk Encryption Algorithm.
  • A Sorting Algorithm, as it does not involve encryption or security aspects.
  • A Data Compression Algorithm, which focuses on reducing data size rather than securing it.
• 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, Encryption Standard, Digital Signature Algorithm, Cryptanalysis, Symmetric-Key Cryptography, Asymmetric-Key Cryptography.

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References

2023

• (Wikipedia, 2023) ⇒ https://en.wikipedia.org/wiki/Cryptography Retrieved:2023-11-27.
  • A cryptographic algorithm is a method in cryptography for performing encryption or decryption—a series of well-defined steps that can be followed as a procedure. An algorithm should be contrasted with a cipher, which is a method for transforming plaintext information into ciphertext, the unreadable form. A cryptographic algorithm works in

2023

• (Wikipedia, 2023) ⇒ https://en.wikipedia.org/wiki/Cryptography Retrieved:2023-11-27.
  • Subcategories:
    • Asymmetric-Key Algorithms: Comprising 3 categories and 14 pages.
    • Broken Cryptography Algorithms: Encompassing 4 categories and 13 pages.
    • Cryptanalytic Algorithms: 2 pages dedicated to this topic.
    • Cryptographic Hash Functions: Featuring 4 categories and 63 pages.
    • Cryptographically Secure Pseudorandom Number Generators: A total of 10 pages.
    • Information-Theoretically Secure Algorithms: Comprising 3 pages.
    • Integer Factorization Algorithms: Includes 26 pages.
    • Padding Algorithms: 3 pages under this section.
    • Primality Tests: A category with 26 pages.
    • Symmetric-Key Algorithms: 3 categories and 2 pages.
  • Pages in Category "Cryptographic Algorithms":
    • Bach's Algorithm, BB84, Beaufort Cipher, Block Cipher Mode of Operation.
    • CDMF, Ciphertext Stealing, Common Scrambling Algorithm, CryptGenRandom, Crypto++, Cryptographic Agility, Cryptographically Secure Pseudorandom Number Generator.
    • Double Ratchet Algorithm, Dynamic Encryption.
    • Equihash.
    • Feedback with Carry Shift Registers, Fuzzy Extractor.
    • Generation of Primes, Geometric Cryptography.
    • Hash Chain, High-Dimensional Quantum Key Distribution, HMAC-Based One-Time Password.
    • Industrial-Grade Prime, ISMACryp.
    • Key Schedule, Key Wrap, Kochanski Multiplication, Kunerth's Algorithm.
    • Linear-Feedback Shift Register, LSH (Hash Function).
    • Master Password (Algorithm), Mental Poker, Modular Exponentiation, Montgomery Modular Multiplication, MOSQUITO.
    • NSA Product Types.
    • PEGASUS.
    • Random Password Generator, Randomness Extractor, Randomness Merger, RC Algorithm, Residual Block Termination, Ring Learning with Errors Key Exchange, Rip Van Winkle Cipher.
    • S-Box, Scrypt, Secret Sharing Using the Chinese Remainder Theorem, SecureLog, Six-State Protocol, Software Taggant, Substitution–Permutation Network, Summation Generator, Supersingular Isogeny Key Exchange, Symmetric-Key Algorithm.
    • Time-Based One-Time Password.
    • Verifiable Random Function.

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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