Embodiments of the present disclosure provide methods and apparatuses for blockchain-based multi-party computation, a device and a medium, relate to blockchain technology in the field of computer technology. An embodiment of the method can include: encrypting business data, to obtain a ciphertext of the business data; hashing the ciphertext of the business data, to obtain a hash result of the business data; sending the hash result of the business data to a blockchain node, so that the blockchain node writes the hash result of the business data into a blockchain; and sending the ciphertext of the business data to a target trusted computing module in a target server, for instructing the target trusted computing module to perform multi-party computation based on the ciphertext of the business data and the hash result of the business data in the blockchain.

An advanced encryption and key exchange (AEKE) algorithm for quantum safe cryptography is disclosed. The AEKE algorithm does not use hard mathematical problems that are easily solvable on a quantum computer with Shor's algorithm. Instead, new encryption algorithm uses simple linear algebra, rank deficient matrix and bilinear equation, which will be easy to understand, fast, efficient and practical but virtually impossible to crack.

An authentication system is provided with: a user device; user side assistance device(s) to assist user authentication that authenticates a user of the user device, and apparatus authentication that authenticates the user device; and an apparatus authentication server device to perform apparatus authentication in association with the user device. The user side assistance device(s) use distributed shares of verification information to perform multi-party computation for user authentication in association with the user device, and use distributed shares of a secret key generated by the user device, to perform multi-party computation for apparatus authentication in association with the user device.

The present disclosure relates to systems, methods, and computer-readable media for enhancing security of communications between instances of clients and servers while enabling rotation of server certificates (e.g., X.509 certificates). The systems described herein involve updating a client list of server certificates (e.g., a certificate thumbprint) without reconfiguring or re-installing a client and/or server application, starting a new session (e.g., a hypertext transfer protocol secure (HTTPS) session), or deploying new code. The systems described herein may passively or actively update a client list of certificates to enable a client to security verify an identity of a server instance in a non-invasive way that boosts security from man-in-the-middle types of attacks.

A secure computation device obtains a first concealed verification value [z].sub.i=[w].sub.i with secure computation by using concealed authentication information [w].sub.i which is preliminarily stored and concealed authentication information [].sub.i which is inputted, obtains a concealed extension field random number [r.sub.m].sub.i [F.sup.] which is a secret sharing value of an extension field random number r.sub.m, obtains a second concealed verification value [y.sub.m].sub.i in which y.sub.m is concealed with secure computation by using the first concealed verification value [z].sub.i, and obtains a third concealed verification value [r.sub.my.sub.m].sub.i with secure computation by using the concealed extension field random number [r.sub.m].sub.i and the second concealed verification value [y.sub.m].sub.i and outputs the third concealed verification value [r.sub.my.sub.m].sub.i.

A method for adding transactions to a blockchain, characterized by the following features: subscribers of the computer network, who are connected by a predefined relation, are determined; multiplication triples are generated as a secret shared among the subscribers; at least one multiplication triple among the multiplication triples is mapped, along with the transactions, to a hash value; if the hash value falls below a predefined target value, a block, which contains the multiplication triple mapped to the hash value, as well as the transactions, is transferred to the blockchain; and a multiparty computation in the computer network is controlled with the remaining multiplication triples.

Computer-implemented systems and methods are disclosed herein for use within secure multi-party computation. A system and method are used for storing an operation preference and a cryptographic preference. A data set is stored based on the operation preference and the cryptographic preference. A determination is made that processing the query involves performing an allowable operation on the data set based on the operation preference.

System and method for digitally signing messages using multi-party computation.

A method for performing spacetime-constrained oblivious transfer between various laboratories of a first party A and various laboratories of a second party B. The method includes providing the spacetime-constrained oblivious transfer to satisfy various conditions. The method further includes encoding, by the laboratories of the first party A, various messages in a quantum state selected from various non-orthogonal quantum states. The method further includes transmitting, by the laboratories of the first party A, the quantum state to a first laboratory of the second party B. The method further includes applying, by the first laboratory of the second party B, a quantum measurement on the quantum state to obtain a classical measurement outcome. The method further includes transmitting, by the first laboratory of the second party B, the classical measurement outcome to the laboratories of the second party B.

A method may include receiving, from a first trusted authority, a secret key specific to a party for use in posting to a blockchain. The method may also include receiving, from a second trusted authority, a correlated randomness component specific to the party and associated with a given temporal segment. The method may additionally include generating a party-generated randomized mask, and computing, using an input from the party, the correlated randomness component, and the party-generated randomized mask in a non-interactive multi-party computation (NIMPC), an NIMPC-encrypted input associated with the party for the given temporal segment. The method may also include encrypting the NIMPC-encrypted input according to a blockchain encryption algorithm to yield a ciphertext, and submitting the ciphertext to a block associated with the given temporal segment in a blockchain.