Quantum computing is expected to reshape the future of cybersecurity. Discover why Public Key Infrastructures (PKIs) are becoming a strategic challenge for electric vehicle charging and how the PrEvent project is exploring post-quantum solutions for tomorrow’s mobility ecosystem.
Digital certificates are the foundation of trust in the electric vehicle charging ecosystem, enabling secure communications and services such as Plug & Charge. However, the emergence of quantum computing raises new challenges for the cryptographic algorithms used by today’s Public Key Infrastructures (PKIs). More specifically, quantum computing mainly threatens the asymmetric cryptographic algorithms that underpin today’s PKIs, digital signatures and key establishment mechanisms. Current PKIs largely rely on RSA and Elliptic Curve Cryptography (ECC), which are expected to become vulnerable in the presence of sufficiently powerful quantum computers. This article explains the role of PKIs in ISO 15118, the risks posed by quantum technologies, and how the PrEvent project is evaluating a post-quantum PKI to help prepare future standards and deployments.
Why are digital certificates essential?
Digital certificates (X.509) [4], commonly used with the TLS protocol [3], are one of the fundamental building blocks of secure digital communications. They are used not only for web browsing, but also to secure communications between software components, such as EVSE-to-CSMS connections or backend-to-backend communications.
They provide several essential security functions:
- Authenticating the identity of a server to a client (e.g. HTTPS websites).
- Authenticating the identity of a client to a server through mutual authentication.
- Ensuring the authenticity and integrity of messages or documents through digital signatures.
- Establishing encrypted communication channels using TLS.
Trust in these certificates relies on a Public Key Infrastructure (PKI). This trust model is based on a chain of trust involving Certification Authorities (CAs and Sub-CAs), which issue and manage certificates, and ultimately on each certificate holder’s ability to prove possession of the private key associated with its certificate. In current deployments, these certificates typically rely on RSA or ECC-based public key cryptography.
The role of certificates in the EV charging ecosystem
Digital certificates play a central role in the electric vehicle charging ecosystem. They are used to authenticate the different actors involved and to secure communications between charging infrastructure components.
They are a key element of the ISO 15118 communication protocol, which defines the communication between electric vehicles and charging stations.
During the establishment of the TLS session, ISO 15118-2 [2] relies on charging station authentication, while ISO 15118-20 [2] introduces mutual TLS authentication between the vehicle and the charging station.
Certificates are also at the heart of the Plug & Charge (PnC) use case. In this scenario, the vehicle stores a Contract Certificate representing the customer’s mobility contract with its eMobility Service Provider (eMSP). This certificate allows the charging infrastructure to authenticate the mobility contract, automatically authorise the charging session without requiring an RFID card or mobile application, and associate the charging transaction with the contract that will be billed.
Why is certificate security critical?
Compromising a PKI or one of its trusted actors represents a major cybersecurity incident because it undermines the trust placed in all certificates issued by that infrastructure.
Depending on the scope of the compromise, the consequences may include:
- Impersonation of a mobility contract, enabling fraudulent charging sessions.
- Unauthorised interactions with V2G ecosystem actors, potentially affecting energy management processes.
- The need to replace or renew thousands—or even millions—of certificates following the compromise of a CA or Sub-CA.
- Long-term confidentiality risks if encrypted communications are intercepted today and decrypted in the future using quantum computers, a scenario commonly referred to as “Harvest Now, Decrypt Later”.
Why should we prepare for the quantum era?
Today’s public key cryptography relies on mathematical problems that are considered computationally infeasible to solve using classical computers.
The emergence of sufficiently powerful quantum computers could challenge this assumption by making widely used asymmetric cryptographic algorithms vulnerable. For example, RSA and Elliptic Curve Cryptography (ECC), which are currently the foundation of most PKIs and TLS deployments, are expected to become vulnerable to quantum attacks.
Although this threat is not yet immediate, operators of critical infrastructures must anticipate this evolution to ensure the long-term security of their systems. Migrating towards post-quantum cryptography is therefore becoming an important strategic objective. Examples of standardised post-quantum algorithms include ML-KEM (formerly CRYSTALS-Kyber) [6] for key establishment and ML-DSA (formerly CRYSTALS-Dilithium) [7] for digital signatures, although the specific algorithms adopted will depend on future standards and deployment requirements.
The PrEvent post-quantum PKI experiment
The PrEvent [5] project aims to strengthen cybersecurity across the electromobility ecosystem by developing and evaluating innovative solutions capable of preventing, detecting, and mitigating cyberattacks.
Within this framework, the consortium is conducting an experimental deployment of a post-quantum PKI.
This work combines the complementary expertise of:
- Gireve, operator of the ISO 15118-2 PKI and future operator of the ISO 15118-20 PKI.
- Vicomtech, a research and technology centre with expertise in post-quantum cryptography.
The objective is to deploy an experimental PKI based on the ISO 15118-20 trust model, where certificates are signed using post-quantum cryptographic algorithms selected and integrated with Vicomtech’s support.
Possible candidate algorithms may include standardised digital signature schemes such as ML-DSA, although alternative post-quantum signature algorithms may also be considered depending on the project objectives and future standardisation efforts.
This experimental PKI will be evaluated in three successive stages:
- within Gireve’s laboratories;
- on UTAC’s testing platforms;
- under real operating conditions at the pilot site in Ljubljana, Slovenia.
Beyond validating the functionality of the experimental PKI, the experimentation may also provide valuable insights into practical aspects such as certificate size, computational overhead, interoperability and deployment considerations associated with post-quantum cryptography.
Scope and future work
This experiment is not intended to provide a fully compliant implementation of an ISO 15118-20 PKI. The current version of the standard specifies cryptographic algorithms that do not yet include post-quantum mechanisms.
However, the results of this work will provide valuable technical feedback regarding the feasibility of integrating post-quantum cryptography into the ISO 15118 ecosystem and may contribute to future discussions within the ISO working groups responsible for the evolution of the standard.
It should also be noted that this experiment focuses on the PKI and certificate infrastructure. Achieving end-to-end quantum-resistant communications will also require the migration of TLS cryptographic mechanisms—particularly key exchange and digital signature algorithms—to post-quantum alternatives.
Current standardisation efforts within the IETF are also exploring the integration of post-quantum and hybrid cryptographic mechanisms into TLS, enabling a gradual migration while preserving interoperability with existing deployments. Similarly, the transition towards post-quantum PKIs is expected to be progressive, requiring interoperability between classical and post-quantum cryptographic mechanisms during the migration period.
Author: Thomas Fousse (Gireve)
References
[1] International Organisation for Standardisation (ISO). (2014). Road vehicles — Vehicle to grid communication interface — Part 2: Network and application protocol requirements. ISO 15118-2:2014. Geneva: International Organisation for Standardisation.
[2] International Organisation for Standardisation (ISO). (2022). Road vehicles — Vehicle to grid communication interface — Part 20: 2nd generation network layer and application layer requirements. ISO 15118-20:2022. Geneva: International Organisation for Standardisation.
[3] Rescorla, E. (2018). The Transport Layer Security (TLS) Protocol Version 1.3. RFC 8446. Internet Engineering Task Force (IETF). Available at: https://datatracker.ietf.org/doc/rfc8446/
[4] Cooper, D., Santesson, S., Farrell, S., Boeyen, S., Housley, R. and Polk, W. (2008). Internet X.509 Public Key Infrastructure Certificate and Certificate Revocation List (CRL) Profile. RFC 5280. Internet Engineering Task Force (IETF). Available at: https://datatracker.ietf.org/doc/rfc5280/
[5] PrEvent Project. (2024). Preventing and detecting cyber threats in the electric mobility ecosystem. Available at : https://www.preventproject.info/
[6] National Institute of Standards and Technology (NIST). (2024). FIPS 203 – Module-Lattice-Based Key-Encapsulation Mechanism Standard (ML-KEM). Available at: https://nvlpubs.nist.gov/nistpubs/fips/nist.fips.203.pdf
[7] National Institute of Standards and Technology (NIST). (2024). FIPS 204 – Module-Lattice-Based Digital Signature Standard (ML-DSA). Available at: https://nvlpubs.nist.gov/nistpubs/fips/nist.fips.204.pdf
Keywords
PrEvent, Post-Quantum Cryptography, Public Key Infrastructure (PKI), Digital Certificates, Cybersecurity, Electric Vehicle, ISO 15118, Plug & Charge (PnC), Vehicle-to-Grid (V2G), TLS Security, Quantum-Resistant, Gireve, Vicomtech, ML-KEM, ML-DSA, Quantum-safe PKI, Post-Quantum TLS