External attack Clause Samples
The 'External attack' clause defines how the parties will address situations where a contract or its terms are challenged or threatened by outside parties, such as through legal action, regulatory intervention, or third-party claims. Typically, this clause outlines the procedures to follow if an external entity attempts to invalidate, modify, or otherwise interfere with the agreement, and may specify the responsibilities of each party in defending against such challenges. Its core practical function is to allocate risk and establish a clear process for responding to external threats, thereby protecting the integrity and enforceability of the contract.
External attack. There is an eavesdropper called Eve who wants to exact the secret key. She can try to use three common method to test the quantum system and exact the secret key, which are “intercept-and-resend”, “control-not” and “fake-participant”. According to the idea before, Eve can get each bit of final key if she gets one operation of any participants. Therefore, this section only discusses a interaction between Eve and one of any participants.
External attack. In the proposed protocol, the decoy state technique is used to prevent external eavesdroppers form attacking the protocol. To achieve that, a sequence of single decoy qubits is randomly selected from the states {|+⟩, |−⟩, |0⟩, |1⟩} and then inserted in random positions into the secret message. The eavesdropper (Eve) cannot distinguish between the decoy-states and secret message states. Eve may try to entangle a secret message state with an auxiliary quantum state (|⟩) by applying a unitary operation () as follows: |0⟩|⟩ = 1|0⟩|00⟩ + 2|1⟩|01⟩, (5) |0⟩|⟩ = 1|0⟩|00⟩ + 2|1⟩|01⟩, (6) |+⟩|⟩ = 1 [|+⟩( | ⟩ + | ⟩ + |0⟩, |0⟩, |0⟩, |1⟩ |0⟩, |0⟩, |1⟩ |0⟩, |1⟩, |−⟩, |+⟩) and
External attack