Unconditionally Secure Quantum Bit Commitment is Impossible
Abstract
The claim of quantum cryptography has always been that it can provide protocols that are unconditionally secure, that is, for which the security does not depend on any restriction on the time, space, or technology available to the cheaters. We show that this claim does not hold for any quantum bit commitment protocol. Since many cryptographic tasks use bit commitment as a basic primitive, this result implies a severe setback for quantum cryptography. The model used encompasses all reasonable implementations of quantum bit commitment protocols in which the participants have not met before, including those that make use of the theory of special relativity.
- Publication:
-
Physical Review Letters
- Pub Date:
- April 1997
- DOI:
- 10.1103/PhysRevLett.78.3414
- arXiv:
- arXiv:quant-ph/9605044
- Bibcode:
- 1997PhRvL..78.3414M
- Keywords:
-
- Quantum Physics
- E-Print:
- 4 pages, revtex. Journal version replacing the version published in the proceedings of PhysComp96. This is a significantly improved version which emphasis the generality of the result