STS: Securing the bridge between legacy and smart
The global energy transition is accelerating, and at its heart lies the Standard Transfer Specification (STS) – the world’s trusted open standard for secure prepayment, writes Riccardo Pucci, Marketing Manager, STS Association.
For more than 30 years, STS has powered energy access across more than 100 countries, ensuring that every token, transaction, and customer interaction is secure and reliable.
Far from being a legacy system, STS is the foundation upon which the smart metering era is being built. It safeguards millions of existing meters while empowering utilities to embrace digital transformation with confidence.
In a world that demands interoperability, transparency, and trust, STS remains the preferred open standard.
Reaffirming global relevance
The recent re-approval of STS by the International Electrotechnical Commission (IEC) underscores its global importance and technical resilience.
Following an independent security review, STS reaffirmed its adoption of the EA11 (128-bit) encryption algorithm, completely replacing the older EA07 (64-bit) version.
This upgrade delivers stronger protection against cyber threats and ensures utilities remain compliant with the latest international security standards.
Interoperability is not an option; it’s the foundation of trust in the digital energy era.
At the same time, obsolete features – such as common keys and magnetic-card functionality – have been retired, streamlining the standard to reflect current and future requirements.
With the expected publication of Edition 3 Amendment 1 by the IEC, STS is once again demonstrating its ability to evolve without disruption.
As a result, STS remains a dynamic, trusted and thriving open standard built for the future.
Bridging legacy and smart infrastructure
A unique strength of STS lies in its dual capability: maintaining legacy prepayment systems while seamlessly supporting the next generation of smart metering.
Through tight integration with the DLMS/COSEM protocol, STS enables digital token delivery, mobile payment platforms, and direct interaction with modern grid infrastructures.
Cover photo: The VUKA Group.
