"A hash function is any function that can be used to map data of arbitrary size to fixed-size values..."
A process of taking input data and transforming it into a fixed size output, often used for checking message integrity.
Cryptography: The study of techniques for secure communication, including encryption, decryption, and authentication.
Hash functions: Mathematical algorithms that produce a fixed-size output (or hash) from any size input. They are used to verify the integrity and authenticity of data.
Collision resistance: The property of a hash function where it is difficult to find two different inputs that produce the same output/hash.
Security properties: A set of attributes that determine the level of trust and confidence in a hash function, including preimage resistance, second preimage resistance, and collision resistance.
Message Authentication Codes (MACs): A type of cryptographic hash function used to ensure data integrity and authenticity.
Digital signatures: A technique used to verify the authenticity and integrity of digital documents, messages, or software.
Password hashing: A technique used to store passwords securely, by hashing them with a salt to protect against dictionary attacks.
Hash tables: A data structure that enables fast lookups using hashes, commonly used in programming languages and databases.
Bloom filters: A probabilistic data structure that allows for efficient membership queries in a set.
Merkle trees: A data structure used to efficiently verify the integrity of large data structures by breaking them into smaller pieces and hashing them.
MD5: An algorithm that creates a 128-bit hash value, often used to verify data integrity.
SHA-1: Secure Hash Algorithm 1, generates a 160-bit hash value and is commonly used in digital signatures and SSL/TLS.
SHA-2: Secure Hash Algorithm 2, includes SHA-256, SHA-384, and SHA-512, each producing a different hash value size.
PBKDF2: Password-Based Key Derivation Function 2, generates a cryptographic key from a password, often used in encryption.
bcrypt: A password-hashing function that uses a variant of the Blowfish encryption algorithm, often used in web applications.
scrypt: A password-based key derivation function that is designed to be computationally intensive and memory-hard, making brute-force attacks more difficult.
Argon2: A password-hashing function that won the Password Hashing Competition in 2015, designed to be memory-efficient and prevent side-channel attacks.
Whirlpool: A cryptographic hash function that produces a 512-bit hash, often used in digital signatures and data integrity verification.
RIPEMD: A family of hash functions that produce various hash lengths (128, 160, 256, or 320 bits), often used in digital signatures and authentication.
Tiger: A cryptographic hash function that produces a 192-bit hash, often used in digital signatures and data integrity verification.
"The values returned by a hash function are called hash values, hash codes, digests, or simply hashes."
"The values are usually used to index a fixed-size table called a hash table."
"Use of a hash function to index a hash table is called hashing or scatter storage addressing."
"Hashing is a computationally and storage space-efficient form of data access that avoids the non-constant access time of ordered and unordered lists and structured trees..."
"They require an amount of storage space only fractionally greater than the total space required for the data or records themselves."
"Use of hash functions relies on statistical properties of key and function interaction: worst-case behaviour is intolerably bad but rare, and average-case behaviour can be nearly optimal (minimal collision)."
"Hash functions are related to (and often confused with) checksums, check digits, fingerprints, lossy compression, randomization functions, error-correcting codes, and ciphers."
"Although the concepts overlap to some extent, each one has its own uses and requirements and is designed and optimized differently."
"The hash function differs from these concepts mainly in terms of data integrity."
"...though there are some hash functions that support variable length output."
"The values are usually used to index a fixed-size table called a hash table."
"Hashing is a computationally and storage space-efficient form of data access that avoids the non-constant access time of ordered and unordered lists and structured trees..."
"Worst-case behaviour is intolerably bad but rare, and average-case behaviour can be nearly optimal (minimal collision)."
"Hash functions and their associated hash tables are used in data storage and retrieval applications to access data in a small and nearly constant time per retrieval."
"Hashing is a computationally and storage space-efficient form of data access that avoids...the often exponential storage requirements of direct access of state spaces of large or variable-length keys."
"The often exponential storage requirements of direct access of state spaces of large or variable-length keys."
"...each one has its own uses and requirements and is designed and optimized differently."
"...each one has its own uses and requirements and is designed and optimized differently."
"...each one has its own uses and requirements and is designed and optimized differently."