Feature · June 29, 2026

ECC Crypto Support for open62541

Security Changes from the OPC UA 1.05.07 Specification Update

By Julius Pfrommer

Elliptic curve graph and cryptographic formulas over a connected network — Elliptic-curve cryptography provides efficient modern security policies for OPC UA.

open62541 v1.5.5 adds support for new OPC UA ECC SecurityPolicies, including the modern ECC_nistP256_AesGcm and ECC_nistP256_ChaChaPoly profiles. This brings elliptic-curve cryptography into open62541’s standard SecurityPolicy set and gives users stronger, more efficient options for secure deployments.

Separately, this release implements the security updates from the OPC UA 1.05.07 specification changes. These updates strengthen the SecureChannel and Session handshakes with channel-bound signatures, ChannelThumbprint handling, updated ECC key negotiation, and ECC user-token authentication using EccEncryptedSecret.

To ensure interoperability, o6 Automation participated in the Interoperability Workshop of the OPC Foundation Security Working Group. All participants were able to connect to our implementation with the 1.05.07 ECC security changes, and our implementation was able to connect to theirs.

The ECC feature was originally contributed to open62541 by Siemens. For an introduction by the authors, see the video below.

OPC UA and open62541 updates.