Port 318PKIX 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)..

transport
tcp · udp

2 transports registered

in transit
cleartext

payload readable on path

assignment
official

registered with iana

risk
2/10

safe

lookups
5,716

rank 857 of 993 · top 86%

Technical Details

what runs on :318

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.

Security Information

exposure of :318

risk score

2/ 10safe

routine exposure. this port is rarely the way in on its own — keep it patched and logged and move on.

security averages 3.8 across 216 ports — this one sits 1.8 below.

in transit

cleartext

credentials and payloads are readable by anyone on path

assignment

official

registered with iana for this service — scanners fingerprint it by number

reachable over

tcp · udp

udp is connectionless — source addresses are trivially spoofed and it is a reflection favourite

security overview

Common Vulnerabilities:

  • Man-in-the-middle attacks attempting to intercept or manipulate timestamp requests and responses.
  • Replay attacks that submit captured timestamp responses to falsely assert data validity.
  • Weak TSA private key management, leading to compromise of the trust anchor.
  • Lack of proper validation of TSA certificates, enabling spoofing.

Common Mitigations:

  • Use strong authentication and mutual TLS to secure communication with the TSA.
  • Implement strict certificate validation and revocation checking for TSAs.
  • Monitor and audit TSA activities to detect signs of misuse or compromise.
  • Regularly update cryptographic algorithms and key sizes according to current best practices.
  • Employ nonce values in timestamp requests to prevent replay attacks.

the 8 most looked-up other ports in security — 216 ports carry that label.

risk mix of the 8 listed

  • caution100%

3 of 8 encrypted