# Mathematical Digest

### Short Summaries of Articles about Mathematics

in the Popular Press

"Quantum Logic with Light, Glass, and Mirrors," by Andrew Shields. *Science,* 13 September 2002.

"Although only a handful of quantum algorithms have been discovered so far,they include important mathematical problems, such as finding the prime factorsof large numbers, the Achilles heel of classical cryptography." From there theauthor predicts that because unlike every other known method quantumcryptography can guarantee the secrecy of encryption keys, it "may soon secureoptical links between different sites of banks or large corporations across ametropolitan area. Thus the first applications for quantum logic are verylikely to be such photonic systems."

*--- Annette Emerson*