a quantum algorithm

Grover's algorithm is a quantum algorithm that offers quadratic speedup over the classical linear search for unsorted lists.

a quantum algorithm for searching specified elements in an unsorted list

Grover’s algorithm is a quantum algorithm for searching specified elements in an unsorted list.

a probabilistic quantum algorithm ) that finds (with high probability

Grover's algorithm is a probabilistic quantum algorithm that finds (with high probability) the unique input to a black box function that produces a particular output value, using $$ O({\sqrt {N}})

a quantum algorithm for searching 'black box' functions

Grover's Algorithm is a quantum algorithm for searching 'black box' functions and could be used to reduce the search space for things like symmetric ciphers and hashes by as much as half (quadratic speedup).