Worked on enhancing key lifecycle management in the walt-id/waltid-identity repository, focusing on cross-platform cryptographic operations for Android and iOS. Developed and delivered a deleteKey feature that enables secure removal of cryptographic keys across both platforms, using Kotlin and Swift to ensure consistent behavior. Established the groundwork for COSE Sign1 signature verification by introducing iOS-specific utilities, including a placeholder for future implementation. Prioritized maintainability and platform parity by aligning source sets and adding expected methods to support multi-platform integration. The work emphasized security feature foundations, setting the stage for robust cryptographic verification in upcoming releases without addressing user-facing bugs.