Trust in the Electric Mobility World

Rumor has it that Google’s new Pixel phone will have wireless charging. While I doubt that’s going to turn many heads, this might:

Inductive charging – an amazing prospect. It’s fascinating how technological expertise from one industry is fueling useful innovation in other industries. While still far from commercial viability, inductive charging could help address range anxiety, among other mental barriers in the minds of potential electric vehicle buyers. Coupling that with the fact that batteries constitute roughly 50% of an electric vehicle’s cost and a major contributor to its weight, there’s no wonder why it’s a big focus for EV ecosystem actors. Today, a fast DC charger could easily cost as much as an electric vehicle itself (including installation costs). I recall reading somewhere that getting a Tesla Supercharger (Tesla's fast charger) for your home is the same as buying two Teslas! If you look at the (rough and extrapolated) costs and the speed of charging from different sources below, you’ll immediately realize what a consumer’s preferred choice would be – fast charging at the cost of public charging! And it’s even better if you can charge while on the move with inductive charging.

The EV Charging Ecosystem

While aspirations for cheap inductive fast charging may seem far-fetched, we’ll get there (round about!) some day. One of the complexities for the slow transition lies in the interdependence of really large industries. In my previous post, I explained how OEMs (car manufacturers), DSOs (from the energy sector) and municipalities (or cities), all have stakes in this ecosystem. And each sector shares a responsibility to help this ecosystem evolve, which is why effective regulation is the single most important factor in this equation. With different actors sometimes having conflicting interests, regulation becomes the impetus, while standards act as catalyst for actors to coexist. Of course, making standards and regulations is far from being a catalytic activity itself! The illustration below gives a simple overview of the main actors involved in this charging ecosystem.

Needless to say, when large industries (like automotive and energy in this case) need to collaborate, it’s mostly a case of collision rather than collaboration. While there would be an abundance of examples, one that comes to mind from personal experience is that of mobile network operators and banks that went head-to-head for mobile financial services in emerging markets - each party seemingly or deliberately oblivious to the others' needs. If an EV has to be charged using the DSO’s infrastructure, should it be allowed to readily exchange information with the grid? And if so, how? What if poor information exchange from the vehicle leads to disruption of electricity for a whole community of houses? Or vice versa, what if the power from the grid exceeds the capacity of the EV's battery? What if a surge in power leads to a total meltdown of the circuits in the EV? Would the DSO be willing to compensate the EV owner in such a case? Perhaps a bit dramatic, but such (or similar) questions can often lead to months and months of rebuttals. While standards can help address a lot of these physical security and information security concerns, it is also imperative that the industry avoids reinventing the wheel, where possible. Like inductive charging or battery technology at large, if a technology has been proven in one field, it is wise to gauge its viability in the other. This is where we step into the age old world of PKI (Public Key Infrastructure).

PKI Security as an Enabler of Collaboration

Luckily, at the time of writing this post, many nice standardization bodies have already gone through the painstaking process of addressing many of these questions (even if some still remain unanswered). Security (both physical and information, but I will use security for ‘information’ security from hereon) is a critical aspect for the handshake between the many actors in this ecosystem. Like many other IoT and connected infrastructure areas, standards on either side have relied on PKI. So there’s no surprise that PKI has emerged as a de facto method for mutual trust between all these actors. Having seen PKI and KMS (key management system) implementations in the energy sector, there seems to be a strong synergy of underlying principals, with obvious tailoring to specific needs to EV charging. Having a proven security mechanism allows all parties to trust the information coming from the other parties. This drastically enhances the capability for demand-response management (managing the storage and flow of energy from the grid to the vehicle, and back) from both sides. What’s even more interesting is a byproduct of this trust-based interaction, called Plug & Charge (PnC). PnC enhances EV driver’s user experience by reducing unnecessary steps from the equation. Just come to the charging point, plug the cable in, and voila! So, not only do all parties benefit from a robust and proven mechanism for information security, the consumer benefits from a smoother experience to charge the vehicle.

How it works

Since this isn't a crash course in PKI and I'm not a technical expert, so I'll try to keep it simple. The standard that governs the norms of this interaction and security between the vehicle and the charge point is ISO 15118. The standard is future-proof for inductive charging as well. The whole mechanism relies on the use of certificate (for simplicity, consider it like a username) and private keys (consider this like a password) to ensure that every entity handles its own asset. The OEM (the EV manufacturer) deploys its own certificate and keys at the time of production, such that a charge point (also called EVSP) can identify it, and securely exchange information with it. Similarly, the EVSP manufacturer may install their own certificates and keys at the time of production. The contractual details like how much credit the EV owner may have or which charging station he may use can be found in a Contract Certificate. This certificate is issued by a mobility service provider (EMSP). An EMSP is a company that the EV owner does a contract with for gaining access to a network of charging stations, operated by a Charging Point Operator (CPO). In most cases, this is a company that has built some sort of a mobile app or website that provides details about charging stations to electric vehicle owners. When a vehicle is put on charge, both the EV and the EVSP (the charge point) already know how to securely communicate with each other. For an analogy, this is a bit like conducting a secure payment transaction on an e-commerce website, through your browser.

More Synergies Ahead

Borrowing from other domains doesn’t end here. During research, I discovered that a concept of roaming and wholesaling also exists in the EV charging world, concepts that Mobile Network Operators work with day in and day out! What piqued my interest further was that the data set used for reconciliation between different EMSPs is called a CDR (charging data record in this case, rather than a call data record for an MNO). Unfortunately, this is where the ISO 15118 limits itself. The world beyond the charge point (EVSE) requires its own trust system between different EMSPs, Charging Point Operators (CPO) and Clearing Houses (CH). But the work of PKI doesn’t end here – it transcends into these roaming and clearing house use cases as well. The illustration below highlights just few of the standards involved (deliberately not named for simplicity, but trust me, they all have names!).

It is fascinating how proven technologies and frameworks are able to withstand the test of evolution, transcending from one ecosystem to another. PKI is just one example, but an extremely important one at that, since trust is a very crucial part of our increasingly connected ecosystems. After all, why fix something that isn't broken! So, till at least quantum computing becomes a reality, long live and prosper, PKI!

DISCLAIMER: All the cool views presented in this post are my own, and do not necessarily reflect the views of my past or present employers.

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