Quantum and classical schemes of position-based cryprography are to transfer confidential message to an abonent with localised space position. Known verification proceedures are based on time-delay measurements of response signals and can`t provide unconditional security, as the eavesdropper can always cheat verifiers with the help of false signals. In order to raise the relative level of security, it is proposed to combine the quantum verification scheme by D.Unruh with multiple-valued logic methods.
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