About Lesson
Keys and Key Management
Keys are the cornerstone of any cryptographic system. Proper management of keys is essential to maintaining the security of cryptographic operations.
Key Properties:
- Secrecy: Keys must remain confidential and known only to authorized users.
- Uniqueness: Each session or communication should use a unique key to prevent reuse vulnerabilities.
- Length: Longer keys generally provide greater security, as they make brute-force attacks more computationally expensive.
Key Management Lifecycle:
- Generation: Keys are generated using cryptographic algorithms with sufficient randomness.
- Distribution: Keys are securely shared between authorized parties. For symmetric cryptography, key exchange protocols like Diffie-Hellman are used; for asymmetric cryptography, public keys are distributed through certificates.
- Storage: Keys must be securely stored to prevent unauthorized access. Hardware security modules (HSMs) are commonly used for this purpose.
- Rotation: Keys should be replaced periodically to limit the impact of a compromised key.
- Revocation: Compromised keys should be immediately revoked and replaced.
- Destruction: Keys must be securely destroyed when no longer needed to prevent recovery by adversaries.