Methods and system for privacy preserving information exchange in a network of electronic devices are disclosed. In one embodiment, a method is implemented in an electronic device to serve as a local party for information exchange between the local party and another electronic device to serve as an aggregator. The method includes storing a plurality of values in a 2D vector, where a first dimension of the 2D vector is based on the number of values, and where each position in the first dimension has one unique value. The method further includes transmitting the 2D vector to the aggregator with masking for the aggregator to prevent the aggregator from decoding the 2D vector, where aggregating the masked 2D vector with masked 2D vectors from other local parties allows decoding of the aggregated 2D vector.

A method performs cryptographic operations on data in a processing device. An iterative operation between a first operand formed by a given number of words and a second operand using a secret key is performed. The iterative operation includes, for each bit of the secret key, applying one of a first set operations and a second set of operations to the first operand and to the second operand depending on of the bit, and conditionally swapping words of the first and the second operand based on a control bit value obtained by applying a logic XOR function to a random bit.

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.

The present disclosure relates to the field of computer technologies and it discloses a method for encrypting a picture performed at a sending device, the method including: obtaining, by a sending device raw data of a to-be-encrypted picture, a first key, a second key, and location information that is used for adding disturbance data to the raw data; generating the disturbance data, and adding the disturbance data to the raw data according to the location information, to obtain first data; encrypting the first data by using the first key, to obtain the second data, and encrypting the first key and the length of the disturbance data by using the second key, to obtain first encrypted data; and sending the second data, the first encrypted data, and the second key to a receiving device.

The present system and method allow the exchange of messages, such as email, between a sender and a recipient while maintaining the data secure and the integrity of the content of the messages. The method and system do not require a user having an account to open a received message. The method comprises the server creating a new communication key upon reception of a request. The communication key is typically valid for a single request to ensure that each request is encrypted using different communication keys. The method typically comprises a client [A] establishing communication on [HANDSHAKE] with one or more servers [B]. The HANDSHAKE generally aims at initializing the encryption key that will be used to exchange information between A and B.

Systems and methods for protecting block cipher computation operations from external monitoring attacks. An example apparatus for implementing a block cipher may comprise a memory device to store instructions for computing a block cipher; and a processing device coupled to the memory device. The processing device performs a Data Encryption Standard (DES) cryptographic operation with multiple rounds of a Feistel structure, each round including a substitution function and a transformation function that combines an expansion function and a permutation function into a single operation. The transformation function transforms a first input portion of an internal state of the respective round and a second input portion of the internal state into a first output portion and a second output portion of data. The second output portion is equal to the first input portion and the first output portion is dependent on a combined permutation output from the transformation function.

The present disclosure relates to a method for protecting a first data item applied to a cryptographic algorithm, executed by a processor, wherein said algorithm is a per-round algorithm, with each round processing contents of first, second and third registers, the content of the second register being masked, during first parity rounds, by the content of a fourth register and the content of the third register being masked, during second parity rounds, by the content of a fifth register.

A method, system, and computer program product for implementing mobile device roaming optimization is provided. The method includes receiving a selection for services associated with a first mobile device provider for activation during travel to a location associated with mobile device roaming attributes with respect to a mobile device of a user. A blockchain structure and a hash masking sensitive data of the user are generated. It is detected that the user and mobile device have traveled to the location and access to the blockchain structure is enabled. Roaming usage attributes of the mobile device are determined. Subsequently, operational functionality of the mobile device at the geographical location is enabled via roaming usage of a network of the second mobile device provider and second hash of consumption related information compliant with data residency is transmitted to the first mobile device provider to facilitate resolution of disputes across entities.

The present invention relates to a computing device for executing a first cryptographic operation of a cryptographic process on useful input data, said computing device comprising a first processor, a second processor and a selection circuit wherein: —said selection circuit is configured: —for receiving, from an input bus, expanded input data obtained by interleaving dummy input data with said useful input data, —for determining positions of the dummy input data in said expanded input data, —and for extracting said dummy input data and said useful input data from the expanded input data based on said determined positions, —said first processor is configured for executing said first cryptographic operation of said cryptographic process on said extracted useful input data to obtain useful output data, —said second processor is configured for executing a second operation on said extracted dummy input data to obtain dummy output data, said computing device being configured for having said operations executed such that leakage generated by said first cryptographic operation is jammed by leakage generated by the second operation.

Aspects of the present disclosure involves receiving an input message, generating a first random value that is used to blind the input message input message to prevent a side-channel analysis (SCA) attack, computing a second random value using the first random value and a factor used to compute the Montgomery form of a blinded input message without performing an explicit Montgomery conversion of the input message, and computing a signature using Montgomery multiplication, of the first random value and the second random value, wherein the signature is resistant to the SCA attack.