William Atkins
Monday, 08 December 2008 20:33
Science -
Space
Page 2 of 3
The use of wormholes could also permit any type of information to be sent between different states of time (past, present, and future).
In the abstract to the three scientists’ paper, they stated,
“The causal self-consistency condition for closed timelike curves can give rise to nonlinear interactions on chronology-respecting qubits [quantum bits, or quantum states].”
“We demonstrate that particular unitary interactions between closed timelike curve qubits and chronology-respecting qubits allow perfect distinguishability of nonorthogonal states.”
“As a result, an adversary with access to closed timelike curves can break the B92, BB84, and SARG04 quantum key distribution protocols. [Quantum key distribution protocols, such as B92, BB84, and SARG04, are schemes developed to securely pass a quantum “key” between two parties within an encryption algorithm.]”
“We offer a constructive proof for generalizing these examples to an arbitrary number of nonorthogonal states. This generalization can thus break any prepare-and-measure quantum key distribution scheme.”
“Our result also implies that a party with access to closed timelike curves can violate the Holevo bound by accessing more than log(N) bits of information from an N-dimensional quantum state.
On page 15 of the December 6, 2008 issue of Science News, Rachel Ehrenberg also writes about the Brun-Harrington-Wilde paper in “A way to crack quantum encryption: Time-travel technique could break supposedly secure codes.”
And, continue with the conclusion of the story on page three.
