Cryptography Research, Inc.

Rambus Inc.

Mark Evan Marson

Helena Handschuh

Ambuj Kumar

Scott C Best

Andrew John Leiserson

Michael Alexander Hamburg

Megan Anneke Wachs

Daniel Robert Beitel

Benjamin Che-Ming Jun

William Craig Rawlings

Winthrop Wu

Ming Chu Li

Gary Bela Bronner

Evan Lawrence Erickson

Michael Hutter

Matthew Evan Orzen

Bart Stevens

Joel Wittenauer

Aspects of the present disclosure involve a method and a system to perform the method to obtain a cryptographic output of a plurality of rounds of a cipher, by performing a plurality of modified rounds of the cipher, each of the modified rounds computing an unmasking transform, an operation of a respective round of the cipher, and a masking transform, the unmasking transform being an inverse of the masking transform of a previous round of the cipher.

Protection of cryptographic substitution-permutation networks from fault injection attacks

Technologies for modal encryption are described. One memory buffer device includes a compression block and an in-line memory encryption (IME) block. The compression block can output compressed data. The IME block can encrypt uncompressed data at a first granularity and encrypt the compressed data at a second granularity, wherein the second granularity is larger than the first granularity.

Memory buffer devices with modal encryption

A value corresponding to a physical variation of a device may be received. Furthermore, helper data associated with the physical variation of the device may be received. A result data may be generated based on a combination of the value corresponding to the physical variation of the device and the helper data. An error correction operation may be performed on the result data to identify one or more code words associated with the error correction operation. Subsequently, a target data may be generated based on the one or more code words.

Generating a target data based on a function associated with a physical variation of a device

Systems and methods for protecting cryptographic keys stored in a non-volatile memory. An example method may comprise: storing a device root key in a non-volatile memory; storing a volatile key in a volatile memory; storing a masked cryptographic key in the non-volatile memory, wherein the masked cryptographic key is produced by combining a cryptographic key and the device root key; storing a masked device root key in the non-volatile memory, wherein the masked root key is produced by combining the device root key and the volatile key; and erasing the device root key from the non-volatile memory.

Protecting cryptographic keys stored in non-volatile memory

Aspects of the present disclosure involve implementations that may be used to protect neural network models against adversarial attacks by obfuscating neural network operations and architecture. Obfuscation techniques include obfuscating weights and biases of neural network nodes, obfuscating activation functions used by neural networks, as well as obfuscating neural network architecture by introducing dummy operations, dummy nodes, and dummy layers into the neural networks.

Protection of neural networks by obfuscation of neural network operations and architecture

A prover chip uses a key multiplier value generated by a proof-of-work function from a challenge value, a random number, and elliptic curve cryptography (ECC) techniques to generate a one-time (or ephemeral) use private key. Similarly, a verifier chip uses the key multiplier value generated by an equivalent proof-of-work function, a public key received from the prover, and ECC techniques to derive a one-time use public key that corresponds to the ephemeral private key generated by the prover chip. The prover chip uses the ephemeral private key to sign the second challenge value and send this signed second challenge value to the verifier chip. The verifier verifies the value it receives using the one-time use public key and if the signature on the second challenge value is valid, authenticates the prover chip to a system.

Authentication using an ephemeral asymmetric keypair

Aspects of the present disclosure involve a method and a system to perform a cryptographic operation that involves a number theoretic transformation of a first vector to a second vector by obtaining components of the first vector, performing a plurality of iterations that each include determining a plurality of output values, wherein each of the plurality of output values is a linear combination of two or more input values, the input values into a first iteration being the components of the first vector and the output values of the last iteration being representative of components of the second vector, and wherein one or more of the output values of at least one iteration are randomized by multiplying at least one input value by a random number, and determining, based on the output values of the last of the plurality of iterations, the components of the second vector.

Protection of transformations by intermediate randomization in cryptographic operations

Described herein are technologies for application authentication and/or data encryption without stored pre-shared keys. In one resource controller, a processing device receives an application identifier (ID) from the application. The processing device provides a current nonce responsive to the application ID and provides the application access to the system resource responsive to determining that a hash of a current key received from the application equals a current tag. The current key is generated by the application based on code of the application and the current nonce. The current tag was previously provided from the application to the resource controller. The current tag can also be hashed by the application using the current key.

Application authentication and data encryption without stored pre-shared keys

Protection of neural networks by obfuscation of activation functions

Protection of neural networks by obfuscation of neural network architecture

A random number generator selects addresses while a 'scoreboard' bank of registers (or bits) tracks which addresses have already been output (e.g., for storing or retrieval of a portion of the data.) When the scoreboard detects an address has already been output, a second address which has not been used yet is output rather than the randomly selected one. The second address may be selected from nearby addresses that have not already been output.

Generating random addresses for nonvolatile storage of sensitive data

A cryptographic accelerator (processor) retrieves data blocks for processing from a memory. These data blocks arrive and are stored in an input buffer in the order they were stored in memory (or other known order)—typically sequentially according to memory address (i.e., in-order.) The processor waits until a certain number of data blocks are available in the input buffer and then randomly selects blocks from the input buffer for processing. This randomizes the processing order of the data blocks. The processing order of data blocks may be randomized within sets of data blocks associated with a single read transaction, or across sets of data blocks associated with multiple read transactions.

Buffer access for side-channel attack resistance

Disclosed are memory encryption systems and methods that rotate encryption keys for robust resistance against side-channel-analysis (SCA)-based attacks on communication paths between an encryption engine within a trust boundary and an external memory component. A key data structure has a plurality of keys that are used to encrypt a plurality of memory blocks in the external memory. The memory blocks encrypted with the oldest key of the key data structure are identified. Encrypted data is read from the identified memory blocks. The encrypted data is decrypted from the identified memory blocks. The data is then re-encrypted using the selected key that is newer than the oldest key, and re-written to the identified memory blocks.

Efficient side-channel-attack-resistant memory encryptor based on key update

A method of and system for gate-level masking of secret data during a cryptographic process is described. A mask share is determined, wherein a first portion of the mask share includes a first number of zero-values and a second number of one-values, and a second portion of the mask share includes the first number of one-values and the second number of zero-values. Masked data values and the first portion of the mask share are input into a first portion of masked gate logic, and the masked data values and the second portion of the mask share are input into a second portion of the masked gate logic. A first output from the first portion of the masked gate logic and a second output from the second portion of the masked gate logic are identified, wherein either the first output or the second output is a zero-value.

Growing community of inventors

Lafayette, CA, United States of America

Mark Evan Marson