Timestamping Authority



The Timestamping Authority (TSA) is a certification services provider that provides certainty about the pre-existence of data in electronic format at a specific time, and that these data has not been altered since that specific moment in time.

ANF AC, as Timestamping Authority (TSA), performs the issuance of Electronic Time Stamps. This service has been designed following international recommendations and standards:

·      IETF RFC 3161  Time-Stamp protocol (TSP).

·      IETF RFC 3628  Policy Requirements for Time-Stamping Authorities (TSAs)

·      IETF RFC 1305 Network Time Protocol (NTP v3)

·      ETSI TS 102 023  Electronic Signatures and Infrastructures (ESI); Policy requirements for time-stamping authorities.

·      ETSI TS 101 861 TSA time-stamping protocol.

More information on the standards followed by ANF AC 

For the creation and signature of the issued stamps, ANF AC has an international infrastructure of servers (UE and Latam), which function as Time Stamp Units (TSU). Each unit uses a qualified electronic certificate that allows its identification.

The Time Stamping Service is an on-line service of high availability and exclusive access for users with valid electronic certificate in valid state issued by ANF AC. 
In electronic signatures, prior to the issuance of the TimeStamp, an OCSP consultation is carried out to determine the validity of the electronic certificate used. 
ANF AC validates the electronic signature generated by the signatory, stamping day and time in universal time coordinated, and signing and granting an exclusive transaction number, as accreditation of the intervention performed. 
TimeStamp is an essential element that allows:
• endow the electronic signature with a long-term validity, 
• long-term custody of documents,
• perform unassisted electronic audit processes, and 
• obtain legal evidences for different purposes, e.g. intellectual property.
ANF AC is one of the few CAs that provides and freely distribute the necessary technology to verify the validity of the Timestamp that it emits, and each TSU manages a list of hash chains that precludes any possible manipulation of the system. The ANF AC's technology has the capability to provide time-stamping services synchronized with the official time of each state in which their TimeStamping Units are located.
The TSU are synchronized with the Spanish Royal Observatory of the Navy (SS-ROA), which is responsible for maintaining the basic unit of Time, declared for legal purposes as the Spanish National Standard of this unit, as well as maintenance and official dissemination of the "Universal Time Coordinated" (UTC) scale, considered for all purposes as the basis of the legal hour throughout the Spanish territory (RD October 23rd, 1992, No. 1308/1992).