Quantum Algorithms Database
Grover's Algorithm
Searches unsorted data in roughly √N steps instead of N, using amplitude amplification.
Year
1996
Inventor(s)
Lov Grover
Speedup Type
Quadratic Speedup
Difficulty
★★★☆☆
The Problem
Finding a specific item in an unsorted list or database without any shortcut like sorting.
How It Works
Repeatedly applies an oracle that marks the correct answer, then amplifies its probability through reflection operations, concentrating probability onto the right answer.
Real-World Impact
Broadly applicable to search and optimization problems; also halves the effective key strength of certain symmetric encryption schemes.