Tag
#quantum algorithms
4 articles
- State of Quantum Computing: Mid-2026 Edition
Five hardware platforms. Four NIST cryptographic standards. Two contested quantum advantage claims. One below-threshold error correction milestone. Seven years after the NISQ era began, quantum computing is at an inflection point. Here is a precise, unsentimental account of where every major platform stands, what has been proved, what remains unproven, and what the next decade realistically looks like.
- QAOA and VQE: The Variational Algorithms That Define the NISQ Era
Before fault-tolerant quantum computers arrive, the algorithms most likely to demonstrate practical quantum advantage are variational: hybrid quantum-classical loops where a shallow quantum circuit estimates an objective function and a classical optimizer tunes the circuit parameters. VQE targets quantum chemistry; QAOA targets combinatorial optimization. Here is how both work, what they have achieved, and where the honest limits of the approach currently lie.
- Grover's Algorithm: The Quantum Speedup That Doesn't Break Everything — But Still Matters
Grover's algorithm searches an unstructured database of N items in O(√N) steps rather than O(N) classically — a quadratic speedup that is provably optimal for quantum computers. Unlike Shor's exponential advantage, the quadratic speedup can be countered by doubling key sizes. But understanding exactly why, and where Grover's algorithm actually applies, is essential for anyone reasoning about quantum cryptographic risk.
- The Algorithm That Broke RSA: Shor's Factoring Algorithm Explained
In 1994, Peter Shor proved that a quantum computer can factor large integers in polynomial time — rendering RSA, ECC, and Diffie-Hellman cryptography conditionally obsolete. Here is exactly how the algorithm works, why the Quantum Fourier Transform is the key, what hardware it would actually require, and what the world is doing about it.
