# US 12,113,898 B2 · Binding with cryptographic key attestation

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- Number: US 12,113,898 B2
- Document ID: US12113898B2
- Status: Granted
- Kind: B2
- Application number: 18/224,518
- Filed: 2023-07-20
- Published: 2023-11-23
- Granted: 2024-10-08
- Earliest claimed: 2021-05-27
- Assignees: Microsoft Technology Licensing, LLC
- Applicants: Microsoft Technology Licensing, LLC
- Inventors: Prabagar Ramadasse; Yordan Rouskov; Mick Healy; Gaurav Dhawan; Venkata Raghuram Pampana; Aleksandr Tokarev; Marc Shepard; Ramachandra Ravitej Vennapusa
- Web page: https://patentgrep.com/patent/US12113898B2

## CPC

- H04L 9/3073: {involving pairings, e.g. identity based encryption [IBE], bilinear mappings or bilinear pairings, e.g. Weil or Tate pairing}
- H04L 9/0866: {involving user or device identifiers, e.g. serial number, physical or biometrical information, DNA, hand-signature or measurable physical characteristics}
- H04L 9/3234: {involving additional secure or trusted devices, e.g. TPM, smartcard, USB or software token (network architectures or network communication protocols for supporting authentication of entities using an additional device in a packet data network H04L63/0853)}
- H04L 9/3265: {using certificate chains, trees or paths; Hierarchical trust model}
- H04L 9/3268: {using certificate validation, registration, distribution or revocation, e.g. certificate revocation list [CRL]}
- H04L 9/0877: {using additional device, e.g. trusted platform module [TPM], smartcard, USB or hardware security module [HSM]}
- H04L 9/50: {using hash chains, e.g. blockchains or hash trees}
- H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M)

## Abstract

Generally discussed herein are devices, systems, and methods for binding with cryptographic key attestation. A method can include generating, by hardware of a device, a device public key and a device private key, based on the device private key, signing a first attestation resulting in a signed first attestation, the first attestation claiming the device private key originated from the hardware, based on the device public key and the signed first attestation, registering the device with a trusted authority, generating, by the hardware, a first application private key and a first application public key, and based on the device private key, signing a second attestation resulting in a signed second attestation, the second attestation claiming the first application private key originated from the hardware, and based on the first application public key and the signed second attestation, registering a first application of the device to a first server.

## Claims

### Claim 1

A device comprising:
a hardware backed key store configured to:
based on a device private key of a device key pair, sign a first attestation resulting in a signed first attestation, the first attestation claiming the device private key originated from a hardware backed key store;
based on the device private key, sign a second attestation resulting in a signed second attestation, the second attestation claiming a first application private key of a first application key pair originated from the hardware backed key store;
communications circuitry configured to:
based on a device public key of the device key pair and the signed first attestation, register the device with a trusted authority;
based on a first application public key of the first application key pair and the signed second attestation, register a first application of the device to a first server; and
receive, from the trusted authority, a certificate attesting the device private key originated from the hardware backed key store.

### Claim 2 (depends on 1)

The device of claim 1, wherein registering the device and the first application includes communication over a transport layer security channel.

### Claim 3 (depends on 1)

The device of claim 1, wherein:
the hardware backed key store is further configured to, based on the device private key, sign a third attestation resulting in a signed third attestation; and
the communications circuitry is further configured to, based on a second application public key of a second application key pair and the signed third attestation, register a second application of the device to a second server.

### Claim 4 (depends on 1)

The device of claim 1, wherein the hardware backed key store is further configured to derive the device public key and the device private key from a hardware backed key that is unique to the hardware backed key store of the device.

### Claim 5 (depends on 1)

The device of claim 1, wherein the device private key is a Rivest-Shafir-Adleman (RSA) signing key or an elliptic curve cryptography (ECC) signing key.

### Claim 6

A method comprising:
based on a device private key of a device key pair, signing a first attestation resulting in a signed first attestation, the first attestation claiming the device private key originated from specified hardware of a device;
based on a device public key of the device key pair and the signed first attestation, registering the device with a trusted authority;
based on the device private key, signing a second attestation resulting in a signed second attestation, the second attestation claiming a first application private key of a first application key pair originated from the specified hardware;
receive, from a trusted authority, a certificate attesting the device private key originated from the specified hardware; and
based on a first application public key of the first application key pair, the signed second attestation, and the certificate, registering a first application of the device to a first server.

### Claim 7 (depends on 6)

The method of claim 6, wherein registering the device and the first application includes communication over a transport layer security channel.

### Claim 8 (depends on 6)

The method of claim 6, further comprising:
based on the device private key, signing a third attestation resulting in a signed third attestation; and
based on a second application public key of a second application key pair and the signed third attestation, registering a second application of the device to a second server.

### Claim 9 (depends on 6)

The method of claim 6, further comprising deriving the device public key and the device private key from a hardware backed key that is unique to the specified hardware.

### Claim 10 (depends on 6)

The method of claim 6, wherein the device private key is a Rivest-Shafir-Adleman (RSA) signing key or an elliptic curve cryptography (ECC) signing key.

### Claim 11

A non-transitory machine-readable medium including instructions stored thereon that, when executed by a device, cause the device to perform operations comprising:
based on a device private key of a device key pair, signing a first attestation resulting in a signed first attestation, the first attestation claiming the device private key originated from hardware of the device;
based on a device public key of the device key pair and the signed first attestation, registering the device with a trusted authority;
based on the device private key, signing a second attestation resulting in a signed second attestation, the second attestation claiming a first application private key of a first application key pair originated from the hardware;
receive, from the trusted authority, a certificate attesting the device private key originated from the hardware; and
based on a first application public key of the first application key pair, the signed second attestation, and the certificate, registering a first application of the device to a first server.

### Claim 12 (depends on 11)

The non-transitory machine-readable medium of claim 11, wherein registering the device and the first application includes communication over a transport layer security channel.

### Claim 13 (depends on 11)

The non-transitory machine-readable medium of claim 11, wherein the operations further comprise:
based on the device private key, signing a third attestation resulting in a signed third attestation; and
based on a second application public key of a second application key pair and the signed third attestation, registering a second application of the device to a second server.

### Claim 14 (depends on 12)

The non-transitory machine-readable medium of claim 12, wherein the operations further comprise deriving the device public key and the device private key from a hardware backed key that is unique to the hardware.