Which type of keying material must have TPI applied?

The requirement for applying TPI, or Two Person Integrity, is specifically designated for all TOP SECRET keying material and any key material labeled as CRYPTO. This requirement is a critical security measure aimed at preventing unauthorized access and ensuring that sensitive information is handled properly. TPI mandates that two authorized individuals must be involved in the management and handling of this keying material, thereby reducing the risk of compromise.

This is particularly important for TOP SECRET information because of the severe consequences associated with its unauthorized disclosure. The additional specifications for designated CRYPTO materials underscore the importance of safeguarding these encryption keys, which are crucial for maintaining the confidentiality and integrity of classified communications.

Other categories of keying material, such as classified documents or encrypted data, do not necessarily require TPI unless they meet the specific criteria of being TOP SECRET or designated CRYPTO, hence why the other options do not align with the TPI requirement.