Meeting PCI-DSS Requirements for Encryption Key Management: Part 1

There are are a few major components of PCI-DSS that need to be addressed when implementing an external key manager into your data encryption equation.  Separation of duties for starters, simply states that those who have access to the sensitive data, such as card holder details or credit card numbers cannot also have access to the encryption keys that protect them.  Conversely, the same can be said for the individuals that are responsible for managing data encryption keys -- they should not have access to the sensitive data for which the keys they are creating are used to protect.  Quite simply, separation of duties is the concept of dividing critical data protection processes between different individuals. This helps reduce the opportunity and likelihood of fraud when processing sensitive data.

I often talk with companies who've until recently considered encryption key management as an afterthought to their security infrastructure.  Often times they would store encryption keys on USB sticks or locally, alongside the encrypted data.  This approach allows individuals within the organization access to both the keys and data, directly conflicting separation of duties.  Utilizing an external encryption key manager to house your encryption keys, as well as implementing a policy where your security team are the only ones managing those keys and your DBA's and users are the only individuals accessing the data, will help move you in the direction of PCI compliance.

But of course there are other pieces to PCI that one should be aware of when it comes to proper encryption key management.  While separation of duties is good practice, there is an additional level of security that can be implemented on the encryption key management side called dual control.  Dual control is a process that requires the involvement of two or more individuals to complete a specified task, such as creating a key, changing its attributes, revoking status, or destroying an encryption from use forever.  Think of dual control as the act of requiring two individuals with two different keys to unlock the launch codes for a nuclear missile.  You certainly wouldn’t want all that responsibility resting on the shoulders of just one person with no oversight in place.  The same can be said for the management of your encryption keys.

To implement dual control on Alliance Key Manager (AKM), our encryption key management HSM, you'd first active it in the AKM configuration file of the hardware appliance.  Then the two Security Admins responsible for key management would install our Java based admin console into their work environments and configure them to communicate with the key manager over a secure TLS connection.  Once this is established, the first Security Admin would authenticate to the key server and set an 'Authorized Administrator' time period.  This allows the the first Admin to specify a window of time (in minutes) where the other Admin can log onto the key manager and perform their duties.  Taking this approach to key creation and management adds that additional layer of security to your encryption key environment.

In Part II of 'Meeting PCI-DSS Requirements for Key Management'  I will discuss the importance of capturing your audit logs and transporting them to a collection server off the key manager device as well as dig into the concept of split knowledge and how AKM meets that requirement. Until then, download our white paper on encryption key management requirements for PCI.