Methods and architectures for secure ranging

Patent metadata

Field	Value
Publication number	US-2020336303-A1
Application number	US-201816643237-A
Country	US
Kind code	A1
Filing date	Jul 3, 2018
Priority date	Sep 28, 2017
Publication date	Oct 22, 2020
Grant date	—

Abstract

Embodiments described herein enable the generation of cryptographic material for ranging operations in a manner that reduces and obfuscates potential correlations between leaked and secret information. One embodiment provides for an apparatus including a ranging module having one or more ranging sensors. The ranging module is coupled to a secure processing system through a hardware interface to receive at least one encrypted ranging session key, the ranging module to decrypt the at least one encrypted ranging session key to generate a ranging session key, generate a sparse ranging input, derive a message session key based on the ranging session key, and derive a derived ranging key via a key derivation cascade applied to the message session key and the sparse ranging input, the derived ranging key to encrypt data transmitted during a ranging session.

First claim

1 - 25 . (canceled)

26 . A ranging apparatus comprising:
a ranging module including one or more ranging sensors, the ranging module coupled to a secure processing system through a hardware interface to receive at least one encrypted ranging session key, the ranging module to decrypt the at least one encrypted ranging session key to generate a ranging session key, generate a sparse ranging input, derive a message session key based on the ranging session key, and derive a derived ranging key via a key derivation cascade applied to the message session key and the sparse ranging input, the derived ranging key to encrypt data transmitted during a ranging session; and a cryptographic engine to derive at least the message session key and derived ranging key via a key derivation function, the cryptographic engine to derive the message session key via application of the key derivation function to the ranging session key and derive the derived ranging key via application of the key derivation cascade to the message session key and the sparse ranging input.

27 . The ranging apparatus as in claim 26 , wherein the key derivation function is based on a keyed-hash message authentication code or a cipher-based message authentication code.

28 . The ranging apparatus as in claim 26 , wherein the key derivation cascade includes a nested cascade of multiple key derivation functions, the key derivation cascade is to enhance resistance of the ranging module to a side channel attack.

29 . The ranging apparatus as in claim 26 , wherein the sparse ranging input includes diversification data having bits of an anti-replay counter value distributed throughout.

30 . The ranging apparatus as in claim 29 , wherein the diversification data is an input parameter of one or more key derivation functions of the key derivation function cascade.

31 . The ranging apparatus as in claim 30 , the anti-replay counter value to be additionally used to generate a secure preamble for a ranging frame, wherein the ranging frame is a data packet transmitted or received during the ranging session and the sparse ranging input is to enhance resistance of the ranging module to a side channel attack during execution of the key derivation cascade.

32 . The ranging apparatus as in claim 26 , the ranging module to determine a time of flight for data transmitted during the ranging session and determine a range based on the time of flight.

33 . A method of securing a ranging operation, the method comprising:
receiving a ranging session key and an anti-replay counter value, the anti-replay counter value used to generate a secure preamble for a ranging frame; deriving a message session key based on the ranging session key; generating a sparse ranging input based on the anti-replay counter value and diversification data; and deriving a derived ranging key via the sparse ranging input and the message session key, encrypting data transmitted within the ranging frame via the derived ranging key, wherein deriving the derived ranging key includes providing the sparse ranging input and the message session key to a cascade of multiple key derivation functions, wherein the ranging frame is a data packet transmitted or received during a ranging session of the ranging operation.

34 . The method as in claim 33 , wherein generating the sparse ranging input includes spreading bits of the anti-replay counter value throughout the diversification data.

35 . The method as in claim 33 , wherein the diversification data is an input parameter of one or more key derivation functions of the cascade of multiple key derivation functions.

36 . A data processing system comprising:
a secure processing system including a secure processor and a secure processor firmware, a secure boot read only memory (ROM) and a cryptographic accelerator and a secure storage for storing one or more private keys for use in a cryptographic system; an application processing system which includes a boot ROM and one or more system buses, the application processing system configured to execute one or more user applications and an operating system; a system memory coupled to one or more system buses to store the operating system and the one or more user applications; and a ranging module including one or more ranging sensors, the ranging module coupled to the secure processing system through a hardware interface to receive at least one encrypted ranging session key, the ranging module to decrypt the at least one encrypted ranging session key to generate a ranging session key, generate a sparse ranging input, derive a message session key based on the ranging session key, and derive a derived ranging key via a key derivation cascade applied to the message session key and the sparse ranging input, the derived ranging key to encrypt data transmitted during a ranging session.

37 . The data processing system as in claim 36 , the ranging module additionally comprising a
cryptographic engine to derive at least the message session key and derived ranging key via a key derivation function.

38 . The data processing system as in claim 37 , the cryptographic engine to derive the message session key via application of the key derivation function to the ranging session key and derive the derived ranging key via application of the key derivation cascade to the message session key and the sparse ranging input.

39 . The data processing system as in claim 38 , wherein the key derivation function is based on a keyed-hash message authentication code or a cipher-based message authentication code.

40 . The data processing system as in claim 36 , wherein the key derivation cascade includes a nested cascade of multiple key derivation functions, the key derivation cascade is to enhance resistance of the ranging module to a side channel attack.

41 . The data processing system as in claim 40 , wherein the sparse ranging input includes diversification data having bits of an anti-replay counter value distributed throughout.

42 . The data processing system as in claim 41 , wherein the diversification data is an input parameter of one or more key derivation functions of the key derivation function cascade.

43 . The data processing system as in claim 42 , the anti-replay counter value to be additionally used to generate a secure preamble for a ranging frame, wherein the ranging frame is a data packet transmitted or received during the ranging session.

44 . The data processing system as in claim 43 , wherein the sparse ranging input is to enhance resistance of the ranging module to a side channel attack during execution of the key derivation cascade.

45 . The data processing system as in claim 36 , the ranging module to determine a time of flight for data transmitted during the ranging session and determine a range based on the time of flight.

Assignees

• Apple Inc

Inventors

• Sierra Yannick L
• Chen Zhimin
• Icart Thomas

Classifications

• H04L9/50

  using hash chains, e.g. blockchains or hash trees · CPC title

• H04W12/041

  Key generation or derivation · CPC title

• H04W12/03

  Protecting confidentiality, e.g. by encryption · CPC title

• H04L63/0492

  by using a location-limited connection, e.g. near-field communication or limited proximity of entities · CPC title

• H04L63/0428

  wherein the data content is protected, e.g. by encrypting or encapsulating the payload · CPC title