Cryptographic Implementation Testing: When Encryption Fails to Protect — 日本企業向けガイド

Encryption is only as strong as its implementation. Cryptographic testing evaluates: algorithm selection (are modern, recommended algorithms used? are deprecated algorithms like MD5, SHA-1, or DES present?), key management (how are encryption keys generated, stored, rotated, and destroyed?), TLS/SSL configuration (protocol versions, cipher suites, certificate validation, HSTS), random number generation (is the application using cryptographically secure random number generators?), password hashing (bcrypt/scrypt/Argon2 vs MD5/SHA), and implementation correctness (custom cryptographic implementations are almost always flawed — is the application using well-tested libraries correctly?). The most common finding: applications that use encryption but store keys alongside the encrypted data, effectively negating the protection.