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Attack the ‘ping-pong ’ protocol without eavesdropping (2004).
| Content Provider | CiteSeerX |
|---|---|
| Author | Cai, Qing-Yu |
| Abstract | Bostr.. om and Felbinger [1] have presented a ping-pong communication protocol which allows the information transferred in a deterministic secure manner. The security of this ping-pong protocol is based on an entangled pair of qubits. And the proof of the case of eavesdropping attack is correct. The aim of this Comment, however, is to point out that the information Bob gains from Alice is not reliable, i.e., the message can not be transmitted successfully from Alice to Bob if this ‘ping-pong ’ protocol is not modified. In the ‘ping-pong ’ protocol, it utilizes the property that one bit of information can be encoded in the states ψ ±>, which is completely unavailable to anyone who has only access to one of the qubits. To gain information from Alice, Bob prepares two qubits in the Bell state ψ +> = (1 / √ 2)( 0> 1> + 1> 0>). Then he stores one qubit and sends the other one to Alice through the quantum channel. Alice can decide to the control or the message mode randomly. In message mode, Alice performs a unitary operation σA z to encode the information ‘1 ’ or does nothing to encode the information ‘0’. Then she sends it back. Bob can get Alice’s information by a Bell measurement. In control mode, Alice performs a measurement in the basis Bz = { 0>, 1>}. Using the public channel, she sends the result to Bob, who then also switches to control mode and performs a measurement in the same basis Bz. Bob compares his own result with Alice’s result. If both results coincide, Bob knows that Eve is in line and stops the communication. Else, Bob sends next qubit to Alice and this communication continues. It has been proven that any information Eve gains |
| File Format | |
| Publisher Date | 2004-01-01 |
| Access Restriction | Open |
| Subject Keyword | Ping-pong Protocol Basis Bz Entangled Pair Alice Result Information Bob Gain Quantum Channel Bell State Public Channel Bell Measurement Control Mode Ping-pong Communication Protocol Next Qubit Information Eve Gain Message Mode Unitary Operation Deterministic Secure Manner Alice Information |
| Content Type | Text |
