Average-case complexity
Average-case complexity is the branch of complexity theory that measures an algorithm's resource needs on typical inputs drawn from a probability distribution, introduced by Leonid Levin in 1984.
Cryptographic hash function
A cryptographic hash function, also called a one-way hash function, maps data of any size to a fixed-length output, designed so that reversing it or finding collisions is infeasible.
Cryptographically secure pseudorandom number generator
A cryptographically secure pseudorandom number generator (CSPRNG) is a generator whose output stays unpredictable to an adversary even if the algorithm and part of the output are known.
Disk encryption theory
As a branch of cryptography, Disk encryption theory studies encryptable storage sectors under the constraint that ciphertext must match plaintext size, shaping FDE modes and security definitions.
Lattice-based cryptography
Lattice-based cryptography (lattice cryptography) is public-key cryptography whose security rests on hard lattice problems, making it resistant to quantum computer attacks; NIST standardized ML-KEM and ML-DSA in 2024.
One-way function
A one-way function is a function that is easy to compute on every input but hard to invert, the foundational assumption of modern cryptography that has never been proved to exist.