Power Repowering with Cryptographic Device Identity Authentication

Solution Overview

Problem

Existing power systems lack efficient methods to uniquely identify and authenticate power requestors, especially in environments where devices connect to networks with varying power demands, leading to potential security vulnerabilities and inefficiencies.

Innovation Solution

Implementing a system that uses cryptographic authentication to verify the identity of power-consuming devices through a combined power/data interface, enabling secure and efficient power delivery by integrating power management integrated circuits and secure tunnels for rapid authentication and authorization.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If cryptographic authentication is implemented for power delivery, then security against Man-in-the-Middle attacks is improved, but authentication time and system complexity increase

Engineering Contradiction:

ImprovesecurityVSAvoidauthentication time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The system performs cryptographic authentication in advance during device connection establishment. The authenticator and authenticated device exchange cryptographic credentials and establish secure sessions before power delivery begins, so that subsequent power transactions can proceed without repeated full authentication cycles.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent introduces an authentication intermediary layer that manages cryptographic credentials and session tokens. This intermediary handles the complex cryptographic verification processes, shielding the power delivery system from direct computational overhead while maintaining security. The intermediary can cache authentication results and manage credential renewal transparently.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If cryptographic authentication is implemented for power delivery, then security against Man-in-the-Middle attacks is improved, but device complexity increases

Engineering Contradiction:

ImprovesecurityVSAvoidsystem complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The system divides cryptographic authentication functionality into separate modular components: an authenticator module that verifies credentials, an authenticated device module that provides credentials, and a power delivery module that enforces authentication results. This segmentation allows each component to be optimized independently and simplifies integration into existing power delivery infrastructure.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces an authentication intermediary layer that manages cryptographic credentials and session tokens. This intermediary handles the complex cryptographic verification processes, shielding the power delivery system from direct computational overhead while maintaining security. The intermediary can cache authentication results and manage credential renewal transparently.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Productivity

If fast restart capability is enabled for repowering, then productivity is improved, but security verification may be compromised

Engineering Contradiction:

Improverepowering speedVSAvoidsecurity verification

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The system performs cryptographic authentication in advance during device connection establishment. The authenticator and authenticated device exchange cryptographic credentials and establish secure sessions before power delivery begins, so that subsequent power transactions can proceed without repeated full authentication cycles.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent maintains continuous authentication state across power delivery sessions. Once a device is authenticated, the system preserves the authentication context and credential validity, allowing rapid resumption of power delivery after interruptions without requiring complete re-authentication, thus maintaining both speed and security.

Inventive Principle:

Principle #20Continuity of useful action

Data Source

PatentUS20250267002A1Fast repowering using cryptographically protected identity

Publication Date: 2025.08.21 CISCO TECHNOLOGY INC

AI summary

A computing device connected to a power source via a combined power/data connection obtains an authentication request from the power source. The authentication request includes a freshness mechanism provided by the power source. The computing device signs an authentication response with a private key associated with a verified identity stored on the computing device. The authentication response includes the freshness mechanism. The computing device provides the authentication response to the power source, and receives power from the power source.