Implementations this specification provide a method and an apparatus for determining data processing model parameters through multiparty cooperation. An example method performed by a data party device includes secretly sharing a first product with a cooperation partner device, based on characteristic data and a share of an original model parameter; communicating with the cooperation partner device, based on the share of the first product and a garbled circuit corresponding to an activation function, to obtain a share of a value of the activation function; secretly sharing a gradient of a loss function with the cooperation partner device, based on the characteristic data and the share of the value of the activation function, to obtain a share of the gradient of the loss function; and computing a share of a new model parameter.

Systems (100) and methods (700) for customizing a cryptographic algorithm. The methods comprise: providing an electronic device with the cryptographic algorithm implementing a permutation function configured to produce a first keystream using bits input thereto, the permutation function comprising a round function .sub.round consisting of a mixing layer in which input bits are combined together; and customizing the mixing layer of the permutation function while the electronic device is in the field. The mixing layer is customized by: receiving, by the electronic device, a first user-software interaction for entering a first bit string comprising a plurality of first arbitrary bits; breaking the first bit string into a plurality of equal length segments each comprising only a portion of the plurality of first bits; and translating each of the equal length segments into irreducible polynomial coefficients and/or an irreducible polynomial identifier.

Physical-layer security is provided by obfuscating or concealing the structure of the signal being transmitted, such that recovery of the underlying information is prohibitively expensive or even impossible. A digital filter implemented within a digital signal processor at the transmitter device introduces an obfuscation function. A digital filter implemented within a digital signal processor at the receiver device removes the obfuscation function. The obfuscation function conceals information bits to be conveyed by a modulated carrier signal. In some versions, the obfuscation function digitally modifies the phases of individual frequency components of the drive signals used to generate the modulated carrier signal. In other versions, the obfuscation function digitally modifies the phases and amplitudes of individual frequency components of the drive signals used to generate the modulated carrier signal.

A system stores data in data units in a cluster in a cloud computing system, the data stored in the data units being encrypted or unencrypted depending on whether encryption is enabled or disabled when storing data in the data units. The system identifies one or more data units to defragment and defragments the identified data units by writing the data from the identified data units to one or more new data units and by releasing the identified data units for storing new data. The system encrypts unencrypted data from the identified data units when writing the data from the identified data units to the one or more new data units.

A method for communicating magnetic resonance imaging (MRI) information wirelessly includes detecting an MRI system emission sequence, and identifying at least one parameter of the sequence. The at least one parameter identified is cross-correlated. A first initial condition for a first chaotic coded sequence and a second initial condition for a second chaotic coded sequence are determined based on the at least one parameter. The method further includes obtaining, from a modulation symbol mapped to MRI information generated at a local coil responsive to the sequence, a real component of the symbol and an imaginary component of the symbol. The real component of the symbol is encrypted based on the first initial condition, and the imaginary component of the symbol is encrypted based on the second initial condition. The encrypted real component and imaginary component of the symbol are wirelessly transmitted.

A hybrid method and system for data encryption significantly reduces the computational cost of encryption and reduces the cost of the processors needed to perform encryption and decryption.

The present invention discloses a chaos nanonet device including a nanonet material having metallic and semiconductive properties dispersed on a substrate and an electrode array composed of a plurality of electrodes that has a selected domain size on the nanonet material, and a PUF security apparatus based on the chaos nanonet device.

A method, apparatus and computer program product for secure communication includes receiving a message for transmission from a transmitting node to a receiving node. The message is split into a plurality of channels and each channel receives an identical copy of the message. Noise data is added to each version of the message. The noise data is different for a respective copy of the message than any other version of the message thus producing a plurality of ciphers each for a respective channel. The ciphers are transmitted via the respective channels from the transmitting node to the receiving node.

A cryptographic key generator for a first optical transceiver includes a photodetector that receives a continuous wave light beam received via an optical channel from a second optical transceiver. The generator samples and quantizes signals from the photodetector during a plurality of intervals to generate respective samples representing respective numbers of photons incident on the photodetector during each of the plurality of intervals. The generator creates a first cryptographic key from the plurality of digital values. The second optical transceiver receives a continuous wave light beam from the first transceiver and performs the same functions to create a second cryptographic key. Due to the reciprocal nature of the channels, the first and second cryptographic keys match.

Provided are methods and systems for invalidating user security tokens. An example method may include providing, by one or more nodes in a cluster, a list of revoked security tokens. The method may include receiving, by the one or more nodes, an indication of invalidating a user security token associated with a user device. The indication may include a request from the user to invalidate the user security token. The method may further include, in response to the receiving, adding, by the one or more nodes, the user security token to the list of revoked security tokens. The user security token can be added to the list of revoked security tokens prior to the expiration time of the user security token. The method may further include replicating, by the one or more nodes, the list of revoked security tokens between further nodes of the cluster.