Key Management

Key management encompasses everything involved with generating, recording, transcribing, distributing, installing, storing, changing, and using keys. It includes proper disposal of keying materials, the keys themselves, and equipment or systems that may have any key-related data remaining in them when turned off. It is the total control of cryptographic keys. Each of these steps in key management is an opportunity to protect the system or to compromise it. Attacks against keys and key management are far more likely to occur and be more successful than attacks against the cryptographic algorithms they use. For these reasons, key management must be rigorous and disciplined.

Kerckhoffs's principle shows us that the encryption and decryption keys are the true strength of any cryptosystem.

All else must be assumed to be known; algorithms are published and publicly analyzed and challenged. Hardware and software implementations are relatively easy to reverse engineer, especially since they are in commercially available forms. This means that key management is the single most critical activity in keeping that system secure and safe for use.

Key Recovery

Key recovery is a backup mechanism that ensures an organization can have continued access to its own encrypted information in the event keys are lost or somehow damaged.

Experts have proposed several methods of key recovery, such as key escrow, key registration, or digital wallets. These strategies all use some form of common trusted directories or other storage structures in which keys are stored (or vaulted). Some levy policy requires that cryptographic keys be registered with the security department or the vault custodian. Each of these strategies transfers trust from the key user to the key escrow or registration authorities (RAs) and places additional authentication burdens on the processes used for placing keys in the vault and retrieving them for use, and on the security of the escrow vault's storage.

One method is multiparty key recovery, which splits a key into multiple parts; each part would be secured and given to different trusted entities. If the actual original keys were lost, the parts stored with the parties could be retrieved, allowing the organization to recover the original keys. Multiparty key recovery is an example of establishing dual control processes. Hardware key management systems, for example, often require two or more administrators to be physically present and log in to the system to perform critical key management tasks.

Another form of key recovery, often proposed by governments, legislatures, and others, would require that any privately used encryption systems contain some form of built-in "law ful code breaking" or backdoor feature. Presumably, law enforcement or national intelligence officials would only use this to break the encryption on anything protected with that system when authorized to do so by a court. This has been roundly rejected by most electorates, business communities, and civil rights activists.