On the Los Alamos Preprint site (xxx.lanl.gov) today: quant-ph/9910072 [abs, src, ps, other] : Title: Quantum secure identification using entanglement and catalysis Authors: Howard N. Barnum Comments: 7 pages; no figures I consider the use of entanglement between two parties to enable one to authenticate her identity to another over a quantum communication channel. Exploiting the phenomenon of entanglement-catalyzed transformations between pure states gives a potentially reusable entangled identification token. In analyzing this, I consider the independently interesting problem of the best possible approximation to a given pure entangled state realizable using local actions and classical communication by parties sharing a different entangled state. (15kb) quant-ph/9910073 [abs, src, ps, other] : Title: Quantum Computation with Bose-Einstein Condensation and Capable of Solving NP-Complete and #P Problems Authors: Yu Shi Comments: revtex, preprint, 10 pages, a figure in a jpg file It is proposed that quantum computation can be implemented on the basis of macroscopic quantum coherence of a many-body system, especially the Bose-Einstein condensation. Since a Bose-Einstein condensate is described by a non-linear Schr\"{o}dinger equation, and the non-linearity is tunable, in principle one may build a quantum computer composed of both linear and non-linear gates. Consequently NP-complete and #P problems can be solved. This idea is illustrated by representing the qubit as the atomic Bose-Einstein condensate trapped in a double-well potential. (12kb) NP solvers are always dubious, but this one's more respectable than any I've seen before. -- Mike Stay Programmer / Crypto guy AccessData Corp. mailto:[EMAIL PROTECTED]