If RSA Is Cracked, Here's Plan B New Scientist (09/15/07) Vol. 195, No. 2621, P. 31; Graham-Rowe, Duncan
as it appeared in the September 19, 2007 edition of ACM TechNews.
Two research groups, one from the University of Queensland in Brisbane, Australia, and the other from the University of Science and Technology of China, in Hefei, say they have successfully created quantum computers that can run a routine called Shor's algorithm, a development that could have a profound impact on cryptography and how we protect our banking, business, and e-commerce data. Some say that quantum computing is nowhere near developed enough for real-world code breaking, but others say that cryptography will have to develop beyond current prime-number-based encryption techniques. The ability to run Shor's algorithm indicates the quantum computers are capable of using quantum processes to factorize large prime numbers. Almost every strong encryption system relies on a regular computer's inability to factor such numbers in a reasonable amount of time, exactly what the two groups claim to have done. However, Jon Callas, head of technology at cryptographic software developer PGP, says the work done by the two groups is significantly behind current cryptography techniques. Callas says the researchers only used four qubits, whereas current cryptography uses about 4,000 bits, which would require a quantum computer with about 50 trillion qubits. Eventually, the number of qubits in quantum computing is expected to surpass the point where it can outperform traditional computers and the length encryption keys can reach, but that could be 50 years away. When that point is reached, however, there are other cryptographic systems that even quantum computing will have trouble with. Hash chains, for example, use a sequential encoding process, and there is currently no known way to break them using a quantum computer. Click Here to View Full Article - Web Link to Publication Homepage
