Embodiments of the disclosure provide blockchain-implemented methods and systems for secure data transfer and/or storage via the use of data hiding (e.g. steganography algorithms, watermarking etc). In accordance with one aspect, a data hiding algorithm is applied multiple times to a portion of secret data to embed it in a cover file. This constructs layers of hidden data, e.g. secret data hidden in an image that is then used as secret data in a further cover file and so on. Each layer can incorporate encryption and authentication techniques to further enhance security. The final layer or a compressed version is provided within a blockchain transaction. Additionally or alternatively, the secret data can be split into a plurality of shares. This can be achieved using a splitting scheme such as, for example Shamir's Secret Sharing Scheme. Different shares of the secret data can then be encrypted before being hidden within a cover file. Different cover files can hide different shares, preferably each share being provided on the blockchain in a different transaction. To access the secret data, all of the cover files need to be identified and accessed from the blockchain, the relevant steganography, compression and encryption technique(s) applied to each, and then the secret data is reconstructed.

A method for supporting sharing of travel history of travelers in airports includes receiving, by a trusted entity of the distributed ledger system, a registration request from a traveler via a traveler application. The registration request provides personal information of the traveler to the trusted entity. The method further includes generating, by the trusted entity, a public key for the traveler using an identity-based encryption mechanism and sending, from the trusted entity to the global identity blockchain, a registration transaction with respect to the traveler. The registration transaction comprises the public key of the traveler. The method further includes recording a travel history that includes all travel tickets of the traveler, wherein a Merkle tree of all the travel tickets of the traveler is generated. The Merkle tree has a Merkle root, and the Merkle root of the Merkle tree is stored in the global identity blockchain.

A method for key generation is arranged in a client processor device, by means of which a second public client key P.sub.c′ of the client is generated. The public key P.sub.c′ is formed by a calculation, or sequence of calculations, which does not contain any operation whose result depends exclusively on the nonce s and at least one public value, or the public key P.sub.c′ being formed by a calculation, or sequence of calculations, where into each operation in which the nonce s enters, at least one non-public value enters the first private client key k.sub.c or the second private client key k.sub.c′, for example as a result of the calculation P.sub.c′=(k.sub.c′.Math.s).Math.G+(k.sub.c′.Math.k.sub.c).Math.P.sub.t.

Example embodiments of the present disclosure relate to devices, methods, apparatuses and computer readable storage media for data encryption and decryption. In example embodiments, a first cipher key and a second cipher key are obtained. The first cipher key comprises a vector of cipher elements, and the second cipher key comprises a set of indices corresponding to a subset matrix of a polarizing matrix. A cipher vector is generated by polar coding of a data vector based on the first and second cipher keys and the polarizing matrix. The data and cipher vectors are combined for encryption of the data vector.

A system and method for preventing hacking of blockchain is proposed. The system includes a cryptocurrency owner configured to own a cryptocurrency wallet storing a cryptocurrency, a public key, and a private key, and capable of setting monitoring-subjected data and monitoring-excluded data, a hacking countermeasure system configured to check status of the cryptocurrency wallet by being connected to the cryptocurrency owner to receive the cryptocurrency and the public key, invalidate a hacking transaction when the hacking transaction matching the monitoring-subjected data is received, and allow the cryptocurrency to be traded by opening the cryptocurrency wallet with the private key and process transaction details into a block file when a monitoring-excluded transaction matching the monitoring-excluded data is received, and a blockchain network configured to receive the block file from the hacking countermeasure system and duplicate the block file into a plurality of block files to distribute and store each block file.

Data privacy is a major concern when accessing and processing sensitive medical data. Homomorphic Encryption (HE) is one technique that preserves privacy while allowing computations to be performed on encrypted data. An encoding method enables typical HE schemes to operate on real-valued numbers of arbitrary precision and size by representing the numbers as a series of polynomial terms.

A method of transmitting data in a storage device includes encrypting original data based on a homomorphic encryption algorithm to generate encrypted data, generating a parameter for regeneration of a ciphertext higher than an operation level of the encrypted data by using the encrypted data and a key value, and transmitting the encrypted data and the parameter to an external host device.

Systems and methods to perform validation of authentication of a security device in a decentralized network are disclosed. In one aspect, embodiments of the present disclosure include a method which can be implemented on a system to, identify telemetry associated with the successful authentication. The telemetry is further in a distributed ledger in the decentralized network and can be used to determine validity of an authentication attempt of the security device by a second user device.

Devices can be configured to implement distributed ledgers capable of immutably recording ledger entries that have validated version identifiers. The devices can include network interfaces, memory and processors. Processors can be configured to obtain ledger entries including version identifiers and version authenticator values, determine software versions that correspond to version identifiers, determine that version identifiers are valid based on version authenticator values, obtain challenges using cryptographic systems, wherein challenges are based on ledger entries, and/or broadcast blocks that incorporate ledger entries to securely add blocks to distributed ledgers. Blocks can be capable of being validated by using cryptographic systems to obtain proofs based on challenges.

The present disclosure describes a system, method and computer readable medium for verifying the ownership of an article. In one embodiment, one or more physically unclonable functions may be applied to an article and associated with a non-fungible token in order to create a digital fingerprint. The digital fingerprint may then be stored on a blockchain network and utilized to verify and authenticate the ownership of the article.