Quantum Computing

Quantum Computing effect on Public Key Cryptography
In 1994 Shor (via a now famous paper), showed that a quantum computer, if it existed, could easily solve the hard problems that are the foundations of all widely used public key cryptography. This made it clear that quantum computers, when they become a reality, will render systems such as RSA, DSA, Diffie-Hellman, and all Elliptic Curve Cryptography algorithms, insecure. This set off a race to build a quantum computer, a competition that has already passed a number of milestones. Most recently, in November 2009,

NIST unveils precursor to quantum computer
In November 2009, NIST demonstrated a 'universal' programmable quantum processor that could be a module in a future quantum computer – a machine that theoretically could solve some important problems that are intractable today, but would simultaneously undermine the security assumptions upon which most of today’s public key cryptographic algorithms are based.

NIST credits NTRU algorithm with being most resilient to Quantum attacks
One class of public key algorithms is based on properties of a mathematical concept known as a lattice. No algorithms yet invented for a quantum computer have had the potential of undermining the security of these algorithms. In a report titled “Quantum Resistant Public Key Cryptography,” NIST analyzed public key cryptographic algorithms that are believed to be resistant to quantum computing based attacks. NTRU’s lattice-based cryptographic algorithms were found to be the most resilient and practical:

	“Of the various lattice based cryptographic schemes that have been developed, the NTRU family of cryptographic algorithms appears to be the most practical...smallest key size...highest performance""
	- “Quantum Resistant Public Key Cryptography” - NIST