406 results about "Zero-knowledge proof" patented technology

A method for providing a digital signature, "chameleon signatures", which provide the signer of a digital signature exclusive control to disclose the contents of the signed information to third parties. The signatures are closely related to "undeniable signatures", but allow for simpler and more efficient realizations. The method is essentially non-interactive requiring no communication between sender and receiver and do not involve the design and complexity of zero knowledge proofs on which traditional undeniable signatures are based. The method employs a combination of standard digital signing methods with a unique hash functions. These hash functions are characterized by the non-standard property of being collision resistant for the signer but collision tractable for the recipient.

The invention discloses an anonymous transfer method based on a block chain. The method comprises the steps that a first node initiates a transfer transaction request to a second node, and receives public key information returned by the second node; the first node generates transaction information of a current transaction and sends the transaction information to the second node, wherein the transaction information comprises a new currency commitment generated based on the public key information, a transaction amount encrypted based on the public key information, and a zero knowledge proof; thesecond node verifies the transaction amount encrypted based on the public key information, and if the verification is passed, the transaction information is published in a block chain network, so that a miner node can perform verification and bookkeeping on the current transaction; and the miner node verifies proof contents in the zero knowledge proof, and if the verification is passed, the transaction is determined to be valid and the transaction information is recorded in the block chain. The invention furthermore discloses an anonymous transfer system based on the block chain and a computer readable storage medium. According to the method and the system, anonymous transfer is realized, so that the privacy of information of two transaction parties of block chain-based transfer is guaranteed.

A method is provided for an escrow cryptosystem that is essentially overhead-free, does not require a cryptographic tamper-proof hardware implementation (i.e., can be done in software), is publicly verifiable, and cannot be used subliminally to enable a shadow public key system. A shadow public key system is an unescrowed public key system that is publicly displayed in a covert fashion. The keys generated by the method are auto-recoverable and auto-certifiable (abbrev. ARC). The ARC Cryptosystem is based on a key generation mechanism that outputs a public/private key pair, and a certificate of proof that the key is recoverable by the escrow authorities. Each generated public/private key pair can be verified efficiently to be escrowed properly by anyone. The verification procedure does not use the private key. Hence, the general public has an efficient way of making sure that any given individual's private key is escrowed properly, and the trusted authorities will be able to access the private key if needed. Since the verification can be performed by anyone, there is no need for a special trusted entity, known in the art as a "trusted third party". The proof and verification method involves one party proving to a second party that a third party can gain access to an encrypted value. In addition, the system is designed so that its internals can be made publicly scrutinizable (e.g., it can be distributed in source code form). This differs from many schemes which require that the escrowing device be tamper-proof hardware. The system is efficient and can be implemented as a "drop-in" replacement to an RSA or ElGamal cryptosystem. The system is applicable for lawenforcement, file systems, e-mail systems, certified e-mail systems, and any scenario in which public key cryptography can be employed and where private keys or information encrypted under public keys need to be recoverable. The system security relies solely on the security of cipher systems involved whose security has been extensively studied in the past.

A system, device and method of confidential secure custodial transfers of asset between entities utilizing transaction agents implemented via a distributed ledger (e.g. a blockchain). In particular, the transaction agents securely record each of the transactions on the ledger utilizing obfuscated or proxy data state such that information about the transactions cannot be gleaned from the ledger. In particular, the transaction agents are able to enforce business rules of the system by requesting zero-knowledge proofs from participants to the transaction (e.g. sender and recipient) in place of actual data for the transaction. The zero-knowledge proofs are able to be designed to prevent an observer of the distributed ledger from determining any information of the transaction that is taking place.

The invention discloses a method for protecting the privacy of a smart contract of a block chain, which can verify correction of a transaction while covering transaction details, and can verify validity and effectiveness of an operation while protecting the user privacy. The technical scheme of the method is as follows: addition is used for homomorphically encrypting privacy data in the block chain, and non-interactive zero knowledge is generated in the transaction process for proving the effectiveness of the transaction.

The invention provides a remote data completeness verification method facing cloud storage. According to the method, the aggregate signature and specified certifier signature technology is utilized, the verification function on the user data completeness by users and the third party auditors is realized, and meanwhile, the information of users for data completeness is enabled not to be leaked; the verification information transparency control is realized through the zero knowledge proving technology, and when the dispute exists between the users and a server, the third party auditors can generate the undeniable high-confidence-degree proving through the non-interactive zero knowledge proving technology. According to the method, under the condition that a cloud storage service provider is incredible, the accuracy of the cloud data completeness verification can also be ensured, and the method provided by the invention has the advantages that the realization is easy, the cost is low, the data protection performance is high, the third party audit is supported, the privacy protection mechanism is flexible, and the like.

The invention discloses a data storage method based on an identity in cloud computing and an integrity verification method based on the identity in cloud computing, and belongs to the technical field of network security. The data storage method comprises the steps that a cloud user generates a secret key application request carrying a public key generated based on the ID of the cloud user, and sends the secret key application request to a KGC server, and a corresponding private key is generated by the KGC server and sent back to the cloud user through a secure channel; the cloud user conducts block division on files to be uploaded, and generates data block labels of data blocks on the basis of the private key, corresponding file labels are generated by the data block labels, and the file labels and the files are uploaded to a cloud server. When the integrity of the files on the cloud server needs to be verified, integrity verification based on the identity is achieved based on zero-knowledge proof between a verification server and the cloud server. The data storage method based on the identity in cloud computing and the integrity verification method based on the identity in cloud computing are used for cloud storage and integrity verification of storage. When the data storage method and the integrity verification method are applied, management of certificates can be remarkably simplified, and the system complexity is reduced; meanwhile, when integrity verification is conducted, the effectiveness of the public key of the cloud user does not need to be verified, and the system complexity is simplified.

The invention belongs to the field of information safety, and provides a fair electronic voting protocol based on blockchain. According to the fair electronic voting protocol, technology such as blockchain, threshold signature scheme, commitment mechanism and zero-knowledge proving and a cryptography method are utilized; based on manners of time commitment and deposit-in-security payment, a no-trusted-third-party electronic voting scheme based on the blockchain and a prime number is presented, and a voting condition of supporting a plurality of candidates can be realized. The fair electronic voting protocol is composed of an initial period, a commitment period, a ballot period and an auditing period. Each voter performs voting on different candidates through selecting different prime numbers which are in one-to-one correspondence with the candidates. The voter pays the deposit-in-security and then performs voting. If a dishonest behavior occurs in the voting process, the deposit-in-security of the voter is used for compensating other voters, thereby ensuring high fairness in the voting process. The fair electronic voting protocol can be used for realizing fair and safe electronic voting.

The invention provides a secure two-party collaboration SM2 signature method consisting of steps of system initialization, negotiation generation of a signature public key, collaborative signature andoutput of a complete signature. According to the secure two-party collaboration SM2 signature method provided by the invention, prior to the negotiation of the signature public key and the collaborative signature, the both communication parties authenticate the identity of the opposite party by using the zero knowledge proof technology, the correctness of outputting the complete signature is ensured by using the promise technology, it is ensured that the first communication party does not need to decrypt a received ciphertext by using the homomorphic encryption technology, the operation of the corresponding ciphertext can be realized, and a timestamp mechanism is added to ensure that the both communication parties can output the complete signature only when the identity of the first communication party, the current time and the position information of the first communication party are consistent, so that the security of the system is greatly improved, the loss caused by the leakage ofa signature private key is reduced, and the man-in-the-middle attack can be prevented. The secure two-party collaboration SM2 signature method provided by the invention has higher security and can beused in an environment in which a communication channel is not safe.

Systems and methods for decentralized distribution of verifiable information, such as financial information, without requiring resort to centralized information system at the time of a query or other request for information. A decentralized method includes the steps of creating a digital wallet, issuing/receiving an issued verifiable digital credential signed by a credential issuer acting as a trust anchor for a claim contained in the verifiable digital credential, storing the verifiable digital credential within the digital wallet, receiving a request for verified information, and providing the verifiable digital credential, including the claim, from the digital wallet. The verification of information may occur as a zero-knowledge proof such that a required standard is verified as satisfied without disclosing more information about a consumer or other user than is absolutely necessary.

The invention discloses a block chain model with the privacy protection function. The block chain model is formed by a minimum trustrank administrator, a private part, and a public part. The minimum trustrank administrator is used for assisting in transaction; the private part is used for defining input information of all sides participating in transaction and sending and receiving of the information and defining relevant calculations during the transaction process and verification of relevant data during the transaction process; and the public part is used for ensuring fairness of the transaction. On the basis of currency encryption, a block chain is constructed by using a distributed anonymous mechanism, zero-knowledge verification, overtime penalties, and packaging methods. Realizationof currency generation and usage, and conversion into basic currency having the privacy protection function relays on zk-SNARK and related data in a ciphertext mode are verified, so that the user is able to realize data verification while the user information is not leaked.

The present invention relates to a secure communication authentication method and system in a distributed environment. By using the method and the system of the present invention, disadvantages in a platform identity certification process in TCG remote certification are alleviated, a method for platform identity certification is expanded, and by combining three technologies, that are, zero-knowledge proof, a Kerberos framework and a virtual TPM, a new verification method is designed, which is mainly intended to make improvement in the aspects in the existing method such as platform information exposure, a trusted third-party bottleneck and complexity avoidance. By using the method and the system of the present invention, the problems of privacy exposure and efficiency in mutual verification between remote servers in the existing distributed system.

The invention provides an attribute protection based multiple authorization center encryption method. The method comprises the steps of setting system parameters first, and then setting a public key and a private key of an authorized person, wherein the public key is used for encrypting data, and the private key is used for generating a private key of a user. The private key of the user is generated by adopting a method of blind calculation, and the private key of the user is used for decrypting messages. According to the method provided by the invention, two-party safety blind calculation is executed between the user and the authorized person; commitment is carried out on a user global identification code (GID) by using a method of completely concealing the commitment, thereby preventing a malicious authorized person from collecting attributes of the user through tracking the user global identification code (GID); a zero-knowledge proof method enables a certifier to let a verifier believe certain attribute information is correct under the condition of not providing any useful information to the verifier, thereby protecting the user privacy; and the method is used for solving problems of access control and safety in cloud calculation, and the system operation efficiency is high.

A method for protecting an item of software, wherein at least one challenge means is associated with said protected item of software, and at least one response means accesses one private keying material. The challenge means has no access to said private keying material. The response means proves to the challenge means that the response means has access to the private keying material using an asymmetric probabilistic proof, e.g., zero knowledge proof. The challenge means validates this proof using the public keying material that corresponds to the response means' private keying material.

A group signature system includes a group manager device, a signer device and a verifier device capable of communicating with each other, each device using a group signature scheme. The group manager device generates a group secret key, a group public key, a member secret key and a signer tracing information. The signer device generates an encrypted text data of the signer tracing information, and a zero-knowledge proof showing that the signer device knows the member secret key and the encrypted text data is correctly generated based on the signer tracing information. The signer device transmits, to the verifier device, a group signature composed of the encrypted text data and the zero knowledge proof, and the message. The verifier device verifies correctness of the group signature and transmits the verified result to the signer device.

Disclosed herein are system, method, and computer program product embodiments for generating and chaining zero-knowledge proofs (“ZKPs”) using proof chaining. A proof may be divided into different components to analyze data in a series and/or parallel manner using chained proof systems. The proof systems may generate hash values indicating that particular functions were applied to the instances of the underlying data. The hash values may prove that a particular function was applied to instances of the underlying data. Using the proof chaining configuration, a data supply system may generate a ZKP allowing a data requesting system to trust a function result without needing to receive the underlying data.

A zero-knowledge proof-based method for protecting user identity privacy comprises the steps as follows: S1, identity secret key requesting: a data user transmits identity secret key generation request information to an identity management centre via an established secure channel; S2, identity secret key generation: the identity management centre uses the identity information of the data user; S3, public parameter setting: public parameters of the data user and a big-data releasing platform are set; S4, zero-knowledge proof protocol execution: an interactive zero-knowledge proof protocol is executed between the data user and the big-data releasing platform; S5, shared secret key requesting: the data user transmits shared secret key generation request information to the identity management centre via the secure channel; S6, shared secret key generation: the identity management centre generates a shared secret key for the data user and the big-data releasing platform; S7, account number and password generation: the big-data releasing platform generates a temporary account number and a corresponding password for the data user and establishes the secure channel.

Provided is a zero-knowledge proof system that allows a discrete-logarithm zero-knowledge proof. The zero-knowledge proof device includes a temporary memory unit that stores pseudorandom numbers and previously determined hash values, a first processing unit that calculates multiple pseudorandom numbers and performs multiple iterations of processing to calculate hash values based on the calculated pseudorandom numbers and the information stored in the temporary memory unit, a second processing unit that determines some of the multiple pseudorandom numbers based on the hash values, and a third processing unit that re-calculates some of the pseudorandom numbers and sends the hash values obtained to a zero-knowledge verification device. The zero-knowledge verification device includes a temporary memory region, a data receiving module that sequentially receives new input data, and a processing module that overwrites hash values including variables and input data, as variables into the temporary memory region each time the input data are received.

Two El Gamal ciphertexts, which are input to a two-input two-output unit switching gates SW forming a permutation network, are randomized with a random number and randomly permuted, and a zero-knowledge proof, which proves the correspondence between the inputs and outputs of the switching gates SW, is output to a verifier without revealing the random number and the random permutation. A decryption unit decrypts ciphertexts from a unit switching gate SW in he last column through the use of a secret key, and proves in zero-knowledge the validity of the decryption without revealing the secret key. A verification unit verifies the proof of each unit switching gate and the proof of the decryption unit.

The invention discloses a homomorphic encryption method for encrypting transaction amount and supporting zero knowledge proof, and belongs to the technical field of information security. The method comprises the following steps: generating a public key, a private key and a zero knowledge parameter according to a zero knowledge proof requirement and a Paillier algorithm; according to a given plaintext, using an encryption algorithm, the public key and the zero knowledge parameter for encryption, and outputting a ciphertext (E, c1 and c2); and according to the given ciphertext, using a decryption algorithm and the private key for decryption, and outputting a plaintext. According to the method, the Paillier homomorphic algorithm is improved; the ciphertext is divided into three parts (E, c1 and c2), the three parts can be used for secreting transaction amount on the whole, and the commitment part E can also be used for proving the zero knowledge range of the transaction amount, so that the Pillier algorithm is combined with the zero knowledge range proof based on FO commitment, and the range proof of the ciphertext is supported. The method can be used for transaction amount encryptionand range proof of an account model, and can also be used for transaction amount encryption and range proof of a UTXO model.