What is the source of industry best practices for key management?
The NIST special publication SP-800-57 provides specific pointers on best practices for both procedurally managing encryption keys, and what to look for in key management systems. In these documents you will find the genesis of most standards regarding encryption key management, including the concepts in PCI DSS 2.0 Section 3.
Also, key management solutions are certified to the FIPS-140-2 standard for cryptographic modules. So FIPS-140 is a source of best practices and standards.
Dual control, separation of duties, and split knowledge have been buzz topics in the key management world lately. What do they mean?
Well, dual control means that at least two people should be required to authenticate before performing critical key management tasks.
Separation of duties means that the individuals managing encryption keys should not have access to protected data such as credit cards, and those that have access to protected data should not have the authority to manage encryption keys.
Split knowledge is defined in the PCI DSS version 2.0 glossary as a “condition in which two or more entities separately have key components that individually convey no knowledge of the resultant cryptography key.”
Are there any standards or best practices regarding “integrated key management?”
“Integrated key management” is a term of art, and not a standard. If “integrated key management” means “we store our encryption keys on the server where the data is,” then that is a bad thing, from a compliance and security point of view.
So, what are the best practices for encryption key management?
First you should follow the key life-cycle and be able to document it. You should always separate the keys from the data. If you follow the PCI guidelines, you are in excellent shape. Finally, I would recommend only using a FIPS 140 certified key management solution.
What are the practical implications of these best practices and core concepts such as “dual control” and “separation of duties?”
One of the practical implications follows from a common fact of system administration. On all major operating systems such as Linux, Windows, and IBM System i (AS/400) there is one individual who has the authority to manage all processes and files on the system. This is the Administrator on Windows, the root user on Linux and UNIX, and the security officer on the IBM i platform. In fact, there are usually multiple people who have this level of authority. In one study by PowerTech, the average IBM System i customer had 26 users with this high level of authority! You just can’t meet PCI and other industry standards for proper key management by storing the encryption keys on the same platform as the data you are trying to protect.
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