Port 318
PKIX Time Stamp Protocol
The PKIX Time Stamp Protocol (TSP) provides a method for associating a trusted timestamp with data, enabling proof that specific content existed at a particular point in time. Commonly used within digital signature frameworks, TSP ensures long-term validation by involving certified time-stamping authorities (TSAs)..
Technical Details
The Public Key Infrastructure X.509 (PKIX) Time Stamp Protocol (TSP), defined in RFC 3161, facilitates a standardized means of affixing a trusted timestamp to arbitrary data. This is achieved by creating a cryptographic hash of the data and submitting it to a Time Stamping Authority (TSA), which appends a timestamp and signs the result. This process guarantees the timestamp is verifiable without revealing the actual content, preserving data privacy.
Communication over port 318 can be handled by both TCP and UDP, typically involving requests from clients to the TSA to obtain a timestamped response. The protocol supports secure message formats based on ASN.1 and CMS (Cryptographic Message Syntax), aligning with PKI infrastructures for certificate validation and non-repudiation.
TSP is widely integrated into PKI systems to support services like digital signature validation, electronic archiving, and compliance auditing. By leveraging cryptographic assurance combined with a trusted time source, PKIX TSP helps maintain the integrity and temporal validity of signed documents and transactions.