The present disclosure relates to a searchable encrypted data sharing method and system based on blockchain and homomorphic encryption, which protects security of sensitive data on the blockchain and realizes searchable and homomorphic calculation of data ciphertext. According to the present disclosure, a data owner encrypts the generated sensitive data and the keywords extracted according to the data with his own key, and then sends the encrypted transaction information to the cloud server. The cloud server verifies the identity of the data owner. If the verification succeeds, the uploaded ciphertext data is stored on a local server, and a ciphertext index, keyword ciphertext and related evidences of the data storage are uploaded to an alliance chain. The alliance chain node verifies the consistency of the uploaded transaction information, and if the verification succeeds, the transaction information is recorded.

The disclosure provides an approach for cryptographic agility. Embodiments include receiving, by a cryptographic agility system associated with an application, a request to establish a secure communication session. Embodiments include, prior to establishing the secure communication session, selecting, by the cryptographic agility system, a first cryptographic technique and a second cryptographic technique for the secure communication session. Embodiments include, during the secure communication session, utilizing the first encryption technique for securely communicating a first set of data. Embodiments include determining that a condition has been met for switching from the first encryption technique to the second encryption technique. Embodiments include, based on the determining that the condition has been met, utilizing the second encryption technique for securely communication a second set of data.

Systems, devices, and methods are provided for secure multiparty computation (MPC) protocols. A first computing entity may send a first cryptographically protected data set to a server and a second computing entity may send a second cryptographically protected data set to the server. The server may lack access to plaintext versions of the data sets. The server may compare cryptographically protected data elements from the first and second data sets as part of a secure MPC protocol to determine certain information regarding the data sets, such as determining which data elements are included in both sets, and perform homomorphic computations according to a homomorphic encryption scheme. The server is accordingly able to determine an encrypted result.

A first system creates and sends encryption key data to multiple data sources. A second system receives data encrypted using the encryption key data from the multiple data sources; the data may include noise data such that, even if decrypted, the original data cannot be discovered. Because the encryption is additively homomorphic, the second system may create encrypted summation data using the encrypted data. The first system separately receives the noise data encrypted using the same technique as the encrypted data. The second system may send the encrypted summation data to the first system, which may then remove the noise data from the encrypted summation data to create unencrypted summation data.

Provided is a method for generating a fully homomorphic code, which includes: generating an Idempotent polynomial; and generating a fully homomorphic code message by using the generated Idempotent polynomial and a message.

Described embodiments provide systems and methods for validating a request to perform an action to access at least one file. A computing device can receive a request from the client, the request being to perform an action to access at least one file and including a first computed value indicative of one or more previous actions on files. The computing device may compare the first computed value to a second computed value maintained by the computing device independently from the first computed value. The second computed value may be indicative of the one or more previous actions on the files. The computing device may perform secondary authentication in addition to primary authentication for the client, responsive to an indication of trustworthiness of the client or the file according to the comparison of the first computed value to the second computed value.

The disclosed exemplary embodiments include computer-implemented apparatuses and methods that validate confidential data based privacy-preserving homomorphic computations involving encrypted data. For example, an apparatus may receive, from a first computing system, encrypted data that includes a first encrypted value representative of at least one of first account data or an element of cryptographic data. Based on the first encrypted value and on second encrypted values, the apparatus may generate encrypted residual values representative of second account data associated with one or more reference accounts, and the apparatus may request and receive a decrypted residual value associated with each of the encrypted residual values from a second computing system. The apparatus may transmit the decrypted residual values to the first computing system, which may validate the first account data based on at least the decrypted residual values and perform operations associated with the validated first account data.

In one set of embodiments, each server executing a secure multi-party computation (MPC) protocol can receive shares of inputs to the MPC protocol from a plurality of clients, where each input is private to each client and where each share is generated from its corresponding input using a threshold secret sharing scheme. Each server can then verify whether the shares of the plurality of inputs are valid/invalid and, for each invalid share, determine whether a client that submitted the invalid share or a server that holds the invalid share is corrupted. If the client that submitted the invalid share is corrupted, each server can ignore the input of that corrupted client during a computation phase of the MPC protocol. Alternatively, if the server that holds the invalid share is corrupted, each server can prevent that corrupted server from participating in the computation phase.

The disclosure relates to an enhanced data security system and method thereof. In some embodiments, the method includes receiving the transactional credential dataset from a user application. The transactional credential dataset is provided by a user to the user application. The method further includes storing the transactional credential dataset in nodes of a graphical embedding storage model. The nodes further store historical credential datasets of the user. Further, the method includes determining a correlation among the historical credential datasets using an artificial neural network (ANN) model and detecting a pattern of the transactional credential dataset based on the correlation. The ANN model is trained based on credential datasets provided by users stored in the nodes of the graphical embedding storage model.

A technique for computationally-efficient privacy-preserving homomorphic inferencing against a decision tree. Inferencing is carried out by a server against encrypted data points provided by a client. Fully homomorphic computation is enabled with respect to the decision tree by intelligently configuring the tree and the real number-valued features that are applied to the tree. To that end, and to the extent the decision tree is unbalanced, the server first balances the tree. A cryptographic packing scheme is then applied to the balanced decision tree and, in particular, to one or more entries in at least one of: an encrypted feature set, and a threshold data set, that are to be used during the decision tree evaluation process. Upon receipt of an encrypted data point, homomorphic inferencing on the configured decision tree is performed using a highly-accurate approximation comparator, which implements a “soft” membership recursive computation on real numbers, all in an oblivious manner.