Abstract: A method for collecting data from a group of entitled members. The method may include receiving, by a collection unit, a message and a message signature; validating, by the collection unit, whether the message was received from any of the entitled members of the group, without identifying the entitled member that sent the message; wherein the validating comprises applying a second plurality of mathematical operations on a first group of secrets, a second group of secrets, and a first part of the message signature; and rejecting, by the collection unit, the message when validating that the message was not received from any entitled member of the group.

Abstract: Techniques and screening messages based on tags in an automotive environment, such as, messages communicated via a communication bus, like the CAN bus. Messages can be tagged with either a binary or probabilistic tag indicating whether the message is fraudulent. ECUs coupled to the CAN bus can receive the messages and the message tags and can determine whether to fully consume the message based on the tag.

Abstract: A method for evaluating flow control integrity, the method may include detecting that a flow reached a flow change command or is about to reach the flow change command, wherein the flow change command belongs to a current software environment, wherein the current software environment is identified by a current environment identifier; retrieving a shadow environment identifier that is a last environment identifier stored in a shadow stack, wherein the shadow environment identifier identifies a software environment having an entry region that was a last entry region accessed by the flow, wherein the entry region comprises a shadow stack update instruction that was executed by the flow; comparing the shadow environment identifier to the current environment identifier; and detecting a potential attack when the shadow environment identifier differs from the current environment identifier.

Abstract: Techniques and screening messages based on tags in an automotive environment, such as, messages communicated via a communication bus, like the CAN bus. Messages can be tagged with either a binary or probabilistic tag indicating whether the message is fraudulent. ECUs coupled to the CAN bus can receive the messages and the message tags and can determine whether to fully consume the message based on the tag.

Abstract: A method for collecting data from a group of entitled members. The method may include receiving, by a collection unit, a message and a message signature; validating, by the collection unit, whether the message was received from any of the entitled members of the group, without identifying the entitled member that sent the message; wherein the validating comprises applying a second plurality of mathematical operations on a first group of secrets, a second group of secrets, and a first part of the message signature; and rejecting, by the collection unit, the message when validating that the message was not received from any entitled member of the group.

Abstract: A method for collecting data from a group of entitled members. The method may include receiving, by a collection unit, a message and a message signature; validating, by the collection unit, whether the message was received from any of the entitled members of the group, without identifying the entitled member that sent the message; wherein the validating comprises applying a second plurality of mathematical operations on first group secrets, second group secrets and a first part of the message signature; and rejecting, by the collection unit, the message when validating that the message was not received from any entitled member of the group.

Abstract: A method for collecting data from a group of entitled members. The method may include receiving, by a collection unit, a message and a message signature; validating, by the collection unit, whether the message was received from any of the entitled members of the group, without identifying the entitled member that sent the message; wherein the validating comprises applying a second plurality of mathematical operations on first group secrets, second group secrets and a first part of the message signature; and rejecting, by the collection unit, the message when validating that the message was not received from any entitled member of the group.

Abstract: In one embodiment, a method for secure computation, includes receiving in a server, over a communication channel from a device external to the server a request to perform a modular exponentiation operation in which an exponent of the operation comprises a secret value, wherein the secret value is not provided to the server, and at least two parameters that encode the secret value in accordance with a polynomial or matrix homomorphic encryption of the secret value computed by the device, and performing in the server, in response to the request, a homomorphic exponentiation using the at least two parameters received from the device without decrypting the secret value in the server, so as to generate an output that is indicative of a result of the modular exponentiation operation.

Abstract: In one embodiment, data for use by a processor is stored in a memory. A network interface communicates over a network with a second device. At a processor, a Somewhat Homomorphic Encryption (SHE) of a plurality of secret shares is generated. The SHE of the plurality of secret shares is sent to the second device. The following is performed in a loop: a first result of a homomorphic exclusive-or operation performed by the second device on the SHE is received, a SHE of the first result is performed, yielding a second result, a SHE of the second result is performed yielding a third result, the third result is transmitted to the second device, and a final SHE result is received from the second device. The received final SHE result is decrypted in order to produce a final Somewhat Homomorphically Decrypted (SHD) output. The final SHD output is then output. Related methods, systems, and apparatus are also described.

Abstract: Techniques and screening messages based on tags in an automotive environment, such as, messages communicated via a communication bus, like the CAN bus. Messages can be tagged with either a binary or probabilistic tag indicating whether the message is fraudulent. ECUs coupled to the CAN bus can receive the messages and the message tags and can determine whether to fully consume the message based on the tag.

Abstract: In one embodiment, a first signature template is received, the first signature template being one of a signature template of a first message or a null template, the first signature template comprising at least the following fields: an aggregation depth field, a message identifier, one of the first message or a result of applying a one way hash function to the first message, a bit vector, an aggregated square random integer mod N, a signature of the first message. A second signature template is created based on the first signature template, the second signature template created as follows: increment the aggregation depth of the first signature template, determine a unique message identifier for a second message, determine a second bit vector, determine an second aggregated square random integer mod N, and calculate a new signature for the second message. Related methods, apparatus, and systems are also disclosed.

Abstract: In one embodiment, a method, system, and apparatus are described, the method, system, and apparatus including generating metadata to be associated with each block of a series of blocks, the generating including, except for an initial block, receiving: a first block, including a signed block, and a second block to be signed, retrieving a first value including a square of a random number, R?2, multiplying R?2 by a nonce, r, and setting r·R?2 to be a square of a first random number, denoted R2, for the second block, retrieving a second value from the first block, the second value including K-bit vector, E?, determining a bit string value of the second block, M, computing E=hash(R2?M?E?), and determining a signature, Sig, for the second block by calculating Sig=r Sig? SE-E?. Related methods, systems, and apparatuses are also described.

Abstract: In one embodiment, data for use by a processor is stored in a memory. A network interface communicates over a network with a second device. At a processor, a Somewhat Homomorphic Encryption (SHE) of a plurality of secret shares is generated. The SHE of the plurality of secret shares is sent to the second device. The following is performed in a loop: a first result of a homomorphic exclusive-or operation performed by the second device on the SHE is received, a SHE of the first result is performed, yielding a second result, a SHE of the second result is performed yielding a third result, the third result is transmitted to the second device, and a final SHE result is received from the second device. The received final SHE result is decrypted in order to produce a final Somewhat Homomorphically Decrypted (SHD) output. The final SHD output is then output. Related methods, systems, and apparatus are also described.

Abstract: In one embodiment, a method for secure computation, includes receiving in a server, over a communication channel from a device external to the server a request to perform a modular exponentiation operation in which an exponent of the operation comprises a secret value, wherein the secret value is not provided to the server, and at least two parameters that encode the secret value in accordance with a polynomial or matrix homomorphic encryption of the secret value computed by the device, and performing in the server, in response to the request, a homomorphic exponentiation using the at least two parameters received from the device without decrypting the secret value in the server, so as to generate an output that is indicative of a result of the modular exponentiation operation.

Abstract: In one embodiment, a method, system, and apparatus are described, the method, system, and apparatus including generating metadata to be associated with each block of a series of blocks, the generating including, except for an initial block, receiving: a first block, including a signed block, and a second block to be signed, retrieving a first value including a square of a random number, R?2, multiplying R?2 by a nonce, r, and setting r·R?2 to be a square of a first random number, denoted R2, for the second block, retrieving a second value from the first block, the second value including K-bit vector, E?, determining a bit string value of the second block, M, computing E=hash(R2?M?E?), and determining a signature, Sig, for the second block by calculating Sig=r Sig? SE-E?. Related methods, systems, and apparatuses are also described.

Abstract: One embodiment of the invention includes a method, including performing, a symmetric homomorphic encryption of a secret SA with a cryptographic key H as input yielding a homomorphic encryption result SA*, sending SA* for mathematical combination by at least one device with at least one secret SB yielding G*, the device A not having access to SB, the at least one device not having access to SA and not having access to H, receiving G*, performing a symmetric homomorphic decryption of data based on G* with H as input yielding a first decrypted output, determining a symmetric cryptographic key KA based on the first decrypted output for secure communication with a first device which is operationally connected to, or includes, a tamper resistant security system including SA and SB therein, securing data using KA yielding secured data, and sending the secured data to the first device.

Abstract: In one embodiment, a first signature template is received, the first signature template being one of a signature template of a first message or a null template, the first signature template comprising at least the following fields: an aggregation depth field, a message identifier, one of the first message or a result of applying a one way hash function to the first message, a bit vector, an aggregated square random integer mod N, a signature of the first message. A second signature template is created based on the first signature template, the second signature template created as follows: increment the aggregation depth of the first signature template, determine a unique message identifier for a second message, determine a second bit vector, determine an second aggregated square random integer mod N, and calculate a new signature for the second message. Related methods, apparatus, and systems are also disclosed.

Abstract: One embodiment of the invention includes a method, including performing, a symmetric homomorphic encryption of a secret SA with a cryptographic key H as input yielding a homomorphic encryption result SA*, sending SA* for mathematical combination by at least one device with at least one secret SB yielding G*, the device A not having access to SB, the at least one device not having access to SA and not having access to H, receiving G*, performing a symmetric homomorphic decryption of data based on G* with H as input yielding a first decrypted output, determining a symmetric cryptographic key KA based on the first decrypted output for secure communication with a first device which is operationally connected to, or includes, a tamper resistant security system including SA and SB therein, securing data using KA yielding secured data, and sending the secured data to the first device.

Abstract: In one embodiment, a method for reducing information leakage in order to counter side channel attacks against a secure execution environment is described, the method including receiving at the secure execution environment a first input comprising a key comprising a sequence of k input elements in a commutative ring, CR, receiving at the secure execution environment a second input comprising a text comprising a sequence of p input elements in the commutative ring, CR, defining an input INP comprising a sequence of j input elements, wherein INP comprises either one or both of the first input or the second input, performing one of a matrix randomization operation or a polynomial randomization operation on the inputs, and producing a randomized output.

Abstract: In one embodiment, a method for secure computation, includes receiving in a server, over a communication channel from a device external to the server a request to perform a modular exponentiation operation in which an exponent of the operation comprises a secret value, wherein the secret value is not provided to the server, and at least two parameters that encode the secret value in accordance with a polynomial or matrix homomorphic encryption of the secret value computed by the device, and performing in the server, in response to the request, a homomorphic exponentiation using the at least two parameters received from the device without decrypting the secret value in the server, so as to generate an output that is indicative of a result of the modular exponentiation operation.