AuthPLC: Authenticating PLC Communication Using ST-based Extended Cryptographic Library

Programmable logic controllers (PLCs) are among the most critical components in industrial control systems (ICS), such as power grids, water systems, and maritime systems, and are responsible for managing system operations. As such, the security and integrity of the control logic of PLCs become the top concern. Attackers can reverse-engineer or forensically analyze PLCs to extract or modify their control logic, potentially causing misbehavior in ICS. In response, prominent vendors such as Siemens and Allen-Bradley have introduced new products and enhanced their firmware with cryptographic components. However, these solutions remain susceptible to unauthorized access due to insufficient authentication mechanisms. Moreover, replacing commercial off-the-shelf PLCs with the latest advanced models is prohibitively difficult for real-world critical infrastructures.