PCI PIN Security v3.1

PIN Security Requirements:
21-3.1 Key components that exist in clear text outside of an SCD must be sealed in individual opaque, pre-numbered, tamper-evident, authenticable packaging that prevents the determination of the key component without noticeable damage to the packaging.
Note: Tamper-evident, authenticable packaging—opacity may be envelopes within tamper-evident packaging—used to secure key components must ensure that the key component cannot be determined. For components written on paper, opacity may be sufficient, but consideration must be given to any embossing or other possible methods to “read” the component without opening of the packaging. Similarly, if the component is stored on a magnetic card, or other media that can be read without direct physical contact, the packaging should be designed to prevent such access to the key component.
Testing Procedures:
21-3.1.a Examine key components and storage locations to verify that components are stored in opaque, pre-numbered, tamper-evident packaging that prevents the determination of the key component without noticeable damage to the packaging.
21-3.1.b Inspect any tamper-evident packaging used to secure key components—e.g., is the package sufficiently opaque to prevent reading of a component—and ensure that it prevents the determination of the key component without visible damage to the packaging.
21-3.1.c Ensure clear-text key components do not exist in non-secure containers such as databases or in software programs.
21-3.1.d Confirm that start-up instructions and other notes used by service technicians do not contain initialization-key values written in the clear (e.g., at the point in the checklist where the keys are entered). 

PIN Security Requirements:
21-3.2 Key components/shares for each specific custodian must be stored in a separate, secure container that is accessible only by the custodian and/or designated backup(s).
Note: Furniture-based locks or containers with a limited set of unique keys— for example, desk drawers—are not sufficient to meet this requirement. Components/shares for a specific key that are stored in separate envelopes, but within the same secure container, place reliance upon procedural controls and do not meet the requirement for physical barriers
Testing Procedures:
21-3.2 Inspect each key component/share storage container and verify the following: 

PIN Security Requirements:
21-3.3 If a key component/share is stored on a token, and an access code (e.g., a PIN or similar access-control mechanism) is used to access the token, only that token’s owner⎯or designated backup(s)⎯must have possession of both the token and its access code.
Testing Procedures:
21-3.3 Interview responsible personnel and observe implemented processes to verify that if a key is stored on a token, and an access code (PIN or similar mechanism) is used to access the token, only that token’s owner—or designated backup(s)—has possession of both the token and its access code.