关键词: 量子密码, 量子密钥协商, 集体噪声, 量子比特效率

Abstract: In order to solve the problem that the quantum key agreement protocols immune to collective noise have low qubit efficiency, two new quantum key agreement protocols are proposed based on logical Bell states. They immune to the collective-dephasing noise and the collective-rotation noise, respectively. Two participants in the protocols can fairly establish a shared secret key by using unitary operations and the delayed measurement technique. The security analysis shows that the two protocols can resist against participant attacks and the corresponding outsider attacks. Finally, the comparison with the quantum key agreement protocols immune to collective noise show that the new protocols have higher qubit efficiency.

Key words: quantum cryptography, quantum key agreement, collective noise, qubit efficiency