[Paper Review] Identity-Based Authentication for On-Demand Charging of Electric Vehicles

Surudhi Asokraj, Tommaso Bianchi+3 more|arXiv (Cornell University)|Aug 4, 2022

RFID technology advancements4 citations

TL;DR

This paper proposes an identity-based, lightweight authentication and billing protocol for on-demand dynamic wireless charging of electric vehicles, using ID-based cryptography and pseudonyms to ensure mutual authentication, privacy, and efficiency. The scheme reduces communication overhead and computation time compared to state-of-the-art protocols, achieving fast, secure, and verifiable charging without pre-purchase requirements.

ABSTRACT

Dynamic wireless power transfer provides means for charging Electric Vehicles (EVs) while driving, avoiding stopping for charging and hence fostering their widespread adoption. Researchers devoted much effort over the last decade to provide a reliable infrastructure for potential users to improve comfort and time management. Due to the severe security and performance system requirements, the different scheme proposed in last years lack of a unified protocol involving the modern architecture model with merged authentication and billing processes. Furthermore, they require the continuous interaction of the trusted entity during the process, increasing the delay for the communication and reducing security due to the large number of message exchanges. In this paper, we propose a secure, computationally lightweight, unified protocol for fast authentication and billing that provides on-demand dynamic charging to comprehensively deal with all the computational and security constraints. The protocol employs an ID-based public encryption scheme to manage mutual authentication and pseudonyms to preserve the user's identity across multiple charging processes. Compared to state-of-the-art authentication protocols, our proposal overcomes the problem of overwhelming interactions and provides public scheme security against the use of simple operations in wide open communications without impacting on performance.

Motivation & Objective

• Address the lack of unified, efficient, and secure protocols for on-demand dynamic wireless charging of electric vehicles.
• Overcome the limitations of existing schemes that require continuous trusted entity interaction, increasing delay and reducing security.
• Enable fast, mutual authentication and billing without pre-purchasing energy, supporting real-time charging decisions.
• Preserve user privacy through identity-based pseudonyms while maintaining public-key security guarantees.
• Design a computationally efficient protocol suitable for high-speed EVs and resource-constrained infrastructure

Proposed method

• Employ an identity-based public key encryption scheme (Boneh-Franklin) to eliminate the need for public key certificates and reduce key management overhead.
• Generate dynamic pseudonyms based on user identity and system parameters to ensure long-term privacy and unlinkability across charging sessions.
• Integrate a hash-chain mechanism for lightweight, fast verification between the EV and roadside units (RSUs) during charging.
• Use a three-party architecture involving the Charging Service Provider Authority (CSPA), Roadside Units (RSUs), and the On-Board Unit (OBU) to decentralize trust and reduce communication latency.
• Apply the Diffie-Hellman problem as the underlying hardness assumption to ensure security against impersonation and replay attacks.
• Minimize message exchanges: only four messages between EV and CSPA, followed by two lightweight messages between EV and RSU, reducing overall communication cost

Experimental results

Research questions

• RQ1 How can mutual authentication and billing be unified in a dynamic wireless charging system without requiring pre-purchase of energy?
• RQ2 Can identity-based cryptography be used to reduce computational and communication overhead while preserving strong security and privacy?
• RQ3 How can the protocol maintain low latency and high efficiency under high-speed EV mobility and constrained infrastructure?
• RQ4 What is the performance trade-off between security, privacy, and computational cost compared to existing schemes?
• RQ5 Can the protocol support verifiable and dispute-resolvable billing without exposing user identities?

Key findings

• The proposed protocol reduces total authentication and charging time to approximately 7.382 + T_CP milliseconds, significantly faster than competing schemes.
• Communication cost is minimized with only 16 messages exchanged, including lightweight hash-based messages of fixed size (e.g., 104–170 bytes), reducing bandwidth usage.
• The protocol achieves public-key security using identity-based encryption, eliminating the need for certificate management and reducing key exchange complexity.
• Computation time is reduced by avoiding repeated hash-chain re-computations; the scheme leverages efficient ID-based operations and pseudonym derivation.
• The system supports privacy-preserving authentication through dynamic pseudonyms, preventing long-term tracking of EVs across multiple charging sessions.
• The protocol enables fair and verifiable billing with tamper-proof OBU logging, allowing dispute resolution between customer and provider using cryptographically secure session records.