公开(公告)号：US20180262326A1

公开(公告)日：2018-09-13

申请号：US15975119

申请日：2018-05-09

Applicant: NXP B.V.

Inventor： WILHELMUS PETRUS ADRIANUS JOHANNUS MICHIELS

IPC: H04L9/06 ,  H04L9/00

CPC classification number: H04L9/0625 ,  H04L9/004 ,  H04L2209/16

Abstract: A method of implementing a method of mapping an input message to an output message by a keyed cryptographic operation, wherein the keyed cryptographic operation includes a plurality of rounds using a Feistel network, including: receiving an input having a first half and a second half; performing, by a basic block, a portion of a round function on the second half to produce a portion of an encoded output, and wherein the basic block provides a portion of the second half as a portion of an encoded first input to a next round; and XORing the portion of the encoded output and a portion the first half to produce a portion of an encoded second input to the next round.

公开(公告)号：US20180276392A1

公开(公告)日：2018-09-27

申请号：US15464711

申请日：2017-03-21

Applicant: NXP B.V.

Inventor： JAN HOOGERBRUGGE ,  WILHELMUS PETRUS ADRIANUS JOHANNUS MICHIELS ,  JOPPE WILLEM BOS

IPC: G06F21/60 ,  G06F12/0891

CPC classification number: G06F21/602 ,  G06F12/0891 ,  G06F12/1408 ,  G06F21/64 ,  G06F21/74 ,  G06F21/79 ,  G06F2212/1021 ,  G06F2212/1052 ,  G06F2212/402 ,  G06F2212/60 ,  H04L9/0643 ,  H04L9/0897 ,  H04L9/3236

Abstract: A data processing system having rich execution environment (REE) and a trusted execution environment (TEE) is provided. In the data processing system, an unsecure memory is coupled to the REE and used for storing encrypted data for use in the TEE. The TEE may have a cache for storing the encrypted data after it is decrypted. The data in both the memory and the cache is organized in blocks, and the cache is smaller than the memory. An interpreter is provided in the TEE, along with a service block in the REE, for fetching and decrypting the data to be stored in the cache. The interpreter checks an integrity of the decrypted data using a hash tree having multiple levels. In the event of a cache miss, all blocks of the hash tree in a path from the data block to a root block are retrieved from the memory in one access operation. A method for operating the cache in the data processing system is also provided.

公开(公告)号：US20170373828A1

公开(公告)日：2017-12-28

申请号：US15194001

申请日：2016-06-27

Applicant: NXP B.V.

Inventor： WILHELMUS PETRUS ADRIANUS JOHANNUS MICHIELS ,  Jan Hoogerbrugge ,  Joppe Willem Bos

IPC: H04L9/00 ,  G06F21/75

CPC classification number: H04L9/002 ,  G06F21/75 ,  H04L2209/16

Abstract: A method for performing a secure function in a data processing system is provided. In accordance with one embodiment, the method includes generating and encoding an encryption key. The encoded encryption key may be encrypted in a key store in a trusted execution environment (TEE) of the data processing system. The encrypted encryption key may encrypted, stored, and decrypted in the key store in the TEE, but used in a white-box implementation to perform a secure function. The secure function may include encrypting a value in the white-box implementation for securing a monetary value on, for example, a smart card. In one embodiment, each time an encryption key or decryption key is used, it is changed to a new key. The method makes code lifting and rollback attacks more difficult for an attacker because the key is stored separately from, for example, a white-box implementation in secure storage.

公开(公告)号：US20200026885A1

公开(公告)日：2020-01-23

申请号：US16040992

申请日：2018-07-20

Applicant: NXP B.V

Inventor： WILHELMUS PETRUS ADRIANUS JOHANNUS MICHIELS ,  GERARDUS ANTONIUS FRANCISCUS DERKS

IPC: G06F21/76 ,  G06F21/75 ,  G06N3/063 ,  G06N3/04 ,  G06N3/08

Abstract: A method for protecting a machine learning model from copying is provided. The method includes providing a neural network architecture having an input layer, a plurality of hidden layers, and an output layer. Each of the plurality of hidden layers has a plurality of nodes. A neural network application is provided to run on the neural network architecture. First and second types of activation functions are provided. Activation functions including a combination of the first and second types of activation functions are provided to the plurality of nodes of the plurality of hidden layers. The neural network application is trained with a training set to generate a machine learning model. Using the combination of first and second types of activation functions makes it more difficult for an attacker to copy the machine learning model. Also, the neural network application may be implemented in hardware to prevent easy illegitimate upgrading of the neural network application.

公开(公告)号：US20180351743A1

公开(公告)日：2018-12-06

申请号：US15607730

申请日：2017-05-30

Applicant: NXP B.V.

Inventor： WILHELMUS PETRUS ADRIANUS JOHANNUS MICHIELS ,  JAN HOOGERBRUGGE

IPC: H04L9/32 ,  H04L29/06

Abstract: A method is provided for performing a cryptographic operation in a white-box implementation on a mobile device. The cryptographic operation is performed in the mobile device for a response to a challenge from a mobile device reader. The mobile device reader includes a time-out period within which the cryptographic operation must be completed by the mobile device. In accordance with an embodiment, a first time period to complete the cryptographic operation on the mobile device is determined. A predetermined number of dummy computations are added to the cryptographic operation to increase the first time period to a second time period. The second time period is only slightly less than the time-out period by a predetermined safety value to make it less likely a relay attack with be successful.