Quantum oblivious transfer achieves secure data choice despite errors
Quantum-State Oblivious Transfer over Quantum Erasure Channels
Information Theory
Summary
The paper tackles how to securely transfer one piece of quantum information out of two choices without revealing the other, even when some data gets lost in transmission. The authors study this problem assuming no shared initial secrets and focus on quantum channels that can erase information. They provide precise limits on how well this transfer can work, both when everyone follows rules and when receivers try to cheat. Their work shows secure quantum oblivious transfer is possible under realistic noisy conditions.
What this means in practice
- •For quantum communication engineers: Design quantum communication systems that securely deliver one of two quantum data items even with erasure noise and no initial shared secrets.
- •For cryptographic protocol developers: Build practical quantum protocols resistant to dishonest receivers in noisy quantum networks using interactive hashing and error testing.
Authors
Remi A. Chou
Abstract
We study quantum-state oblivious transfer over the quantum erasure channel under information-theoretic security guarantees. Specifically, Alice holds two quantum systems, Bob wishes to recover one of them, and the parties have access to independent channel uses and authenticated public classical communication, with no initial shared entanglement. We consider both honest-but-curious and malicious behavior. We establish finite-blocklength converse and achievability bounds, which match in the honest-but-curious setting. The malicious setting construction combines interactive hashing with tests of whether Bob received selected channel outputs, and distributes each input across several qubits so that erasures conceal an entire input from a dishonest receiver, even when the inputs are entangled with an external reference. We also derive fixed-error asymptotic expansions and show that both malicious and honest-but-curious settings have the same capacity.