Worked on security hardening for the zrchain repository by addressing a cryptographic vulnerability in the btcec module of the BTCSuite library. Applied a targeted upgrade to btcsuite version 2.3.4, ensuring the cryptographic dependencies remained current and secure without introducing downtime. The update process included comprehensive dependency management and security patching, with all changes fully documented for traceability and compliance. Focused on maintaining project stability and minimizing risk exposure, the work leveraged Go for implementation and emphasized auditability through detailed commit records. This approach ensured zrchain continued to meet security standards while maintaining operational continuity and robust dependency hygiene.