Secure Cryptographic Implementation Questions

Practices and techniques for implementing cryptography and related security controls in application code so that cryptographic guarantees are preserved in real world systems. Topics include correct algorithm selection and parameter choices, secure random number generation and entropy handling for keys and nonces, safe key generation and lifecycle management, and secure storage and zeroing of sensitive data in memory. Implementation hardening covers constant time implementations to avoid timing attacks, protections against cache and power side channel attacks, proper use of padding and avoidance of padding oracle vulnerabilities, correct initialization vector and nonce usage to avoid reuse, and awareness of compiler and optimization effects that can break security properties. It also covers secure use of cryptographic libraries and avoiding misuse of primitives, secure password hashing choices, avoidance of custom or home grown cryptography, secure error handling to prevent information leaks, secrets management to avoid hard coded credentials, dependency and supply chain management to avoid vulnerable libraries, input validation and output encoding when cryptography interacts with untrusted input, and testing and verification approaches such as code review, static analysis, runtime testing, and fuzzing to find implementation flaws.