Key Management – Recommendations and Best Practices
Cryptographic keys are a vital part of any security system. They do everything from data encryption and decryption to user authentication. The compromise of any cryptographic key could lead to the collapse of an organization’s entire security infrastructure, allowing the attacker to decrypt sensitive data, authenticate themselves as privileged users, or give themselves access to other sources of classified information. Luckily, proper management of keys and their related components can ensure the safety of confidential information.
Key Management is the process of putting certain standards in place to ensure the security of cryptographic keys in an organization. Key Management deals with the creation, exchange, storage, deletion, and refreshing of keys, as well as the access members of an organization have to keys.
Primarily, symmetric keys are used to encrypt and decrypt data-at-rest, while data-in-motion is encrypted and decrypted with asymmetric keys. Symmetric keys are used for data-at-rest since symmetric encryption is quick and easy to use, which is helpful for clients accessing a database, but is less secure.
The way symmetric key systems work and steps listed below.
- A user contacts the storage system, a database, storage, etc, and requests encrypted data
- The storage system requests the data encryption key (DEK) from the key manager API, which then verifies the validity of the certificates of the key manager API and the key manager
- A secure TLS connection is then created, and the key manager uses a key encryption key (KEK) to decrypt the DEK which is sent to the storage systems through the key manager API
- The data is then decrypted and sent as plaintext to the user
Asymmetric key systems work differently, due to their use of key pairs. The steps follow below:
- The sender and recipient validate each other’s certificates via either their private certificate authority (CA) or an outside validation authority (VA)
- The recipient then sends their public key to the sender, who encrypts the data to be sent with a one-time use symmetric key which is encrypted by the recipient’s public key and sent to the recipient along with the encrypted plaintext
- The recipient decrypts the one-time use symmetric key with their own private key, and proceeds to decrypt the data with the unencrypted one-time use key
While these key systems do keep data secure, that makes the cryptographic keys the biggest sources of security concerns for an organization, which is where key management comes in.
To ensure strong security and uniformity across all government organizations, the National Institute of Standards and Technology (NIST) has created Federal Information Processing Standards (FIPS) and NIST Recommendations, referred to as NIST Standards, for sensitive and unclassified information in government organizations. These standards have security methods approved for all government data that is unclassified and sensitive.
NIST Standards
For symmetric algorithms, block cipher-based algorithms, such as AES, and hash function-based algorithms, like SHA-1 or SHA-256, are approved. Block cipher based algorithms iterate through a series of bits called blocks and uses different operations, such as XOR, to permutate the blocks over a series of rounds, leading to the creation of a ciphertext.
Conclusion
Key Management is one of the essential portions of cybersecurity, and therefore should be executed with all the best-practices in mind. Luckily, the government publishes the NIST Standards which recommend the best ways to minimize security risks related to cryptographic keys.
The NIST Standards discuss how keys should be used, what cryptographic algorithms are approved for government work, and what cryptoperiods for keys should be set to. As NIST Standards are updated, it is worth keeping track of to ensure your security system is always up to date.
