9. Which of the following is the best way to securely store an encryption key for a data set in a manner that allows multiple entities to access the key when needed?
Answer: D
Key escrow is the best way to securely store an encryption key for a data set, allowing multiple entities to access the key when needed.
Key escrow involves placing an encryption key in a secure location managed by a trusted third party. This allows designated entities to access the key as needed, ensuring both security and accessibility.
A) Public key infrastructure
Public key infrastructure (PKI) is primarily used for managing digital certificates and public-private key pairs, but it does not inherently provide a mechanism for securely storing and sharing encryption keys among multiple entities. While PKI enables secure communications, it does not facilitate the controlled access to a shared encryption key in the way that key escrow does.
B) Open public ledger
An open public ledger, while useful for transparency and immutability in transactions, does not provide a secure method for storing sensitive encryption keys. Storing keys on a public ledger can expose them to unauthorized access, undermining their security and confidentiality, which is contrary to the requirements of secure key management.
C) Public key encryption
Public key encryption utilizes a public-private key pair to facilitate secure communications but does not inherently address the storage of encryption keys in a way that allows multiple entities to access the same key. This method is more focused on secure transmission rather than the secure, shared storage of keys, making it less suitable for the scenario described.
D) Key escrow
Key escrow is specifically designed for the secure storage of encryption keys, allowing a trusted third party to hold the key while granting access to authorized users. This method ensures that multiple entities can retrieve the key when necessary, balancing security and access requirements effectively.
Conclusion
Key escrow is the most appropriate choice for securely storing an encryption key while enabling access for multiple entities. In contrast, the other options, including public key infrastructure, open public ledgers, and public key encryption, do not provide the same level of control or security for key management, making them unsuitable for this specific need.