Secure Direct Communication Using Quantum Calderbank-Shor-Steane Codes
The notion of quantum secure direct communication (QSDC) has been introduced recently in quantum cryptography as a replacement for quantum key distribution, in which two communication entities exchange secure classical messages without establishing any shared keys previously. In this paper, a quantum secure direct communication scheme using quantum Calderbank-Shor-Steane (CCS) error correction codes is proposed. In the scheme, a secure message is first transformed into a binary error vector and then encrypted(decrypted) via quantum coding(decoding) procedures. An adversary Eve, who has controlled the communication channel, can't recover the secrete messages because she doesn't know the deciphering keys. Security of this scheme is based on the assumption that decoding general linear codes is intractable even on quantum computers.
Quantum Digital Signature Based on Quantum One-way Functions
A quantum digital signature scheme based on quantum mechanics is proposed in this paper. The security of the protocol relies on the existence of quantum one-way functions by fundamental quantum principles. Our protocol involves a so-called arbitrator who validates and authenticates the signed message. This scheme uses public quantum keys publicized by the signatory to verify the validity of the signature and uses quantum one-time pad to ensure the security of quantum information on channel. To guarantee the authenticity of the transmitted quantum states, a family of quantum stabilizer code is employed. The proposed scheme presents a novel method to construct secure quantum signature systems for future secure communications.