Secure EV Charging Billing via Signed Energy Data

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Solution Overview

Problem

Current methods for electric vehicle charging infrastructure lack secure and verifiable billing mechanisms, making it difficult for users to ensure they are charged only for the energy they use, with concerns over data integrity and authenticity during transmission between vehicles, charging stations, and billing centers.

Innovation Solution

A method involving electronic signatures for data packets containing energy measurement data, using unique keys for charging stations and vehicles, ensures data integrity and authenticity by linking time and meter readings inextricably, allowing users to verify billing accuracy through public and private keys.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If electronic signatures and cryptographic methods are implemented to secure billing data, then data integrity and authenticity are improved, but device complexity and computational overhead increase

Engineering Contradiction:
Improvebilling data integrityVSAvoidcryptographic system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

A billing center is introduced as an intermediary between charging stations and users. The billing center receives signed billing data from charging stations, verifies the cryptographic signatures, and presents verified information to users. This intermediary handles the complex verification process centrally, reducing the cryptographic complexity burden on individual charging stations and user devices while maintaining strong security guarantees through centralized validation.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If detailed measurement data is transmitted from charging station to billing center, then billing accuracy is improved, but data transmission volume and processing time increase

Engineering Contradiction:
Improveenergy measurement accuracyVSAvoiddata transmission and processing time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The charging station performs preliminary actions by signing the billing data with its private key before transmission. This pre-signing ensures data integrity is established at the source, allowing the billing center to quickly verify authenticity without needing to re-examine the raw measurement data. The preliminary cryptographic binding of the data reduces the need for extensive validation processing at the billing center, thereby reducing overall processing time while maintaining measurement precision.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP2445746B1Securing the billing of energy drawn at a charging station
Publication Date: 2014.12.17 RWE
  • EP2445746B1 patent drawingFigure 1
  • EP2445746B1 patent drawingFigure 2a~2d
  • EP2445746B1 patent drawingFigure 3

AI summary

The invention relates to a method for the secure billing of a quantity of energy obtained from a charging station. The aim of the invention is to provide customers with transparent and traceable billing. This is achieved by the following steps: detecting at least one measuring device meter reading of a measuring device (10) in the charging station (2), said measuring device measuring the quantity of energy obtained by a vehicle (6) from the charging station (2); generating a data packet (34) comprising at least the measuring device meter reading; generating a signature (36) of the data packet using part of a measuring device key (18a) assigned to the measuring device (10); and transmitting at least the data packet (34) and the signature (36) to a central billing station (22).