In June 2025, Chris Reitter focused on strengthening DER signature parsing within the tkhq/sdk repository. He addressed a critical bug by tightening length validation and clarifying error messages, reducing the risk of misparsing invalid encodings and padding. Through a series of four commits, Chris expanded test coverage to include edge cases while preserving correct DER semantics and maintaining compatibility with existing cryptographic workflows. His work leveraged TypeScript and backend development skills, with a strong emphasis on cryptography and testing. The result was a more robust and resilient error handling path, improving reliability for downstream services that depend on DER parsing.