33 results about "Quantum Fourier transform" patented technology

A system for use in quantum encryption, decryption, and encoding, comprises a photon production sub-system, a transmission channel sub-system, and a data encoding sub-system. The transmission channel sub-system makes use of the combination of quantum state vectors derived from the photon production sub-system for optical communication with quantum key. The data encoding sub-system includes a plurality of dynamic data encoding modules, and at least one of these modules performs to express the quantum key with bases in an individual Hilbert Space, and divides the transmitting data into segments for data encoding with the individual space bases. In addition to the use in data encoding, the sub-system can also improve the signal-decays and the eavesdropping issue within the quantum channel via implementation of the Laplace Transformation unit and the Quantum Fourier Transformation unit.

The invention relates to an efficient and practical quantum secret sharing method based on a d-level single particle. A secret distributor prepares a d-level single particle and uses it as an information carrier for circular transmission between each participant. Each participant encodes its sub-secret into the signal particle through a local unitary operation without quantum storage, which improves the practicability of the scheme. The quantum Fourier transform is used to construct two mutually unbiased ground states on the d-level quantum system, and the quantum unclonability is combined to ensure the unconditional security of the scheme in theory. In the present invention, one d-level particle can share two classical bits, and the number of particles required for wiretapping detection is reduced through a combined wiretapping detection method, so as to ensure that the scheme obtains higher quantum efficiency.

The invention discloses a user agent-based cloud quantum privacy query method. The method includes: using a database to negotiate with the user agent through classical channels to obtain a first shared key; using the database to encrypt the quantum state sequence generated according to the key to generate the first mixed key The sequence is transmitted to the cloud service provider; the cloud service provider performs quantum entrusted calculation on the first mixed sequence to generate the second mixed sequence and transmits it to the user agent; the user agent decrypts the second mixed sequence to generate the third mixed sequence and transmits it to the querying user A group; use the query user to decrypt the third mixed sequence to obtain the query quantum state, and perform quantum privacy query according to the obtained query quantum state. The present invention implements double encryption on the entire entrusted encryption process by means of cloud server entrusted encryption calculation, and improves the efficiency of the entire quantum transmission by utilizing the advantage of quantum Fourier transform to transmit multiple quantum keys at one time.

The present invention relates to a finite-field discrete logarithm quantum solution circuit optimization construction method, comprising: constructing an addition carry gate circuit for finite-field discrete logarithms, so as to realize equivalent conversion of multiplication cyclic group generators; setting the addition carry gate Auxiliary bits, and realize recursively performing the operation of the addition carry gate through the addition quantum circuit; use the addition carry gate circuit to perform the comparison operation, and judge the carry information when the quantum register and the constant are added, so as to realize the optimization of the modulo N addition quantum circuit; through the modulo N The addition operation realizes the multiplication operation, and constructs the modular N multiplication quantum circuit; realizes the modular exponentiation operation through the modular N multiplication operation, and constructs the modular exponentiation quantum circuit; combines the modular exponentiation quantum circuit and the existing quantum Fourier transform quantum circuit, constructs and realizes the finite field A quantum algorithm circuit for solving discrete logarithms. The invention realizes the modular addition process through the logic quantum circuit, reduces the calculation amount and complexity of the logarithm solution, reduces the calculation load of software and hardware, and has strong application prospects.

The invention provides a safety multiparty quantum summation method based on quantum Fourier transform, wherein a transmission particle is transmitted in a tree form. A participant responsible for preparing initial quantum state is assumed to be semi-loyal, so that the participant can wrongly act by following own will but cannot conspire with the others. The method provided by the invention is capable of resisting against the external attack and the participant attack. Especially, one participant cannot acquire the secrete integer sequences of the other participants. The method provided by the invention is safe for the conspired attack applied by at most n-2 participants, wherein n is the number of the participants. Besides, according to the method provided by the invention, the module d is calculated and the summation is calculated in the manner of integer adding integer rather than the manner of bit adding bit.