Cryptography Research, Inc.

Michael Hutter

Scott C Best

Mark Evan Marson

Michael Alexander Hamburg

Helena Handschuh

Michael Tunstall

Elke De Mulder

Pascal Sasdrich

Begül Bilgin

Samantha Gummalla

Bart Stevens

Hardware masking may be used as a countermeasure to make power analysis attacks more difficult. Masking attempts to decouple the secret and/or processed values of a cryptographic algorithm from its intermediate values. One method of masking probabilistically splits each bit of a computation into multiple shares. Mask-share domains (i.e., the wires and gates that perform a computation on a share) are physically spaced to reduce coupling between mask-share domains. The mask-share domains may be connected to the same power supply network. The physical distance between mask-share domains along the power-supply network may be selected to reduce coupling between mask-share domains that may occur via the power supply network. The mask-share domains may each be connected to different on-chip power supply networks.

Share domain arrangements for masked hardware implementations

An input data may be received. A portion of a cryptographic operation may be performed with the received input data at a first function component. During the performance of the cryptographic operation at the first function component, a pre-charge operation may be performed at a second function component. Furthermore, the second function component may be used to perform another portion of the cryptographic operation with a result of the portion of the cryptographic operation performed at the first function component.

Functions with a pre-charge operation and an evaluation operation

Aspects of the present disclosure involve a method and a system to support execution of the method to perform a cryptographic operation involving a first vector and a second vector, by projectively scaling the first vector, performing a first operation involving the scaled first vector and the second vector to obtain a third vector, generating a random number, storing the third vector in a first location, responsive to the random number having a first value, or in a second location, responsive to the random number having a second value, and performing a second operation involving a first input and a second input, wherein, based on the random number having the first value or the second value, the first input is the third vector stored in the first location or the second location and the second input is a fourth vector stored in the second location or the first location.

Protection of cryptographic operations by intermediate randomization

Aspects of the present disclosure calculate masked data shares dynamically inside the CPU boundary, and use a plurality of memory channels to write the masked data shares to an external memory location and/or to read the data shares from that external memory location. Each dynamically generated mask value is uniquely associated with a corresponding memory channel during writing data to the external memory. The modified masked data is unmasked or remasked during a subsequent read operation.

Side-channel-attack-resistant memory access on embedded central processing units

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.

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Vienna, Austria

Michael Hutter