Optimal bounds for semi-honest quantum oblivious transfer
| Autor: | Chailloux, André, Gutoski, Gus, Sikora, Jamie |
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| Rok vydání: | 2013 |
| Předmět: | |
| Zdroj: | Chicago Journal of Theoretical Computer Science, 2016 |
| Druh dokumentu: | Working Paper |
| Popis: | Oblivious transfer is a fundamental cryptographic primitive in which Bob transfers one of two bits to Alice in such a way that Bob cannot know which of the two bits Alice has learned. We present an optimal security bound for quantum oblivious transfer protocols under a natural and demanding definition of what it means for Alice to cheat. Our lower bound is a smooth tradeoff between the probability B with which Bob can guess Alice's bit choice and the probability A with which Alice can guess both of Bob's bits given that she learns one of the bits with certainty. We prove that 2B + A is greater than or equal to 2 in any quantum protocol for oblivious transfer, from which it follows that one of the two parties must be able to cheat with probability at least 2/3. We prove that this bound is optimal by exhibiting a family of protocols whose cheating probabilities can be made arbitrarily close to any point on the tradeoff curve. Comment: Accepted version. 16 pages, new title, results unchanged |
| Databáze: | arXiv |
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