A timestamp is a sequence of characters or encoded information identifying when a certain event occurred, usually giving date and time of day, sometimes accurate to a small fraction of a second. The term derives from rubber stamps used in offices to stamp the current date, and sometimes time, in ink on paper documents, to record when the document was received. Common examples of this type of timestamp are a postmark on a letter or the "in" and "out" times on a timecard. In modern times, usage of the term has expanded to refer to digital date and time information attached to digital data. For example, computer files contain timestamps that tell when the file was last modified, and digital cameras add timestamps to the pictures they take, recording the date and time the picture was taken.
There are some e-commerce applications, such as electronic contract signing, electronic document signing, etc., which are required to have a credible certification that can prove the signing time of the contract or the document. However, the time on user’s computer, mobile phone or server can be modified at will. If the signed contracts or documents attached with the untrusted time, then no one can guarantee the contract signing time is credible. Therefore, contract e-signing and document e-signing require an authoritative third party to provide reliable and non-repudiation timestamping services.
MeSign E-signature services provide users with Adobe trusted timestamping services for free, MeSign Timestamping Service, it is a RFC 3161 compliant timestamping service, it bind a reliable date and time digitally signed by the timestamp certificate in the timestamping server to provide a reliable time proof for the PDF signing application. Please see how it works in the left figure below. The user generates and submits the HASH of the to-be-signed file to the MeSign timestamping server to request signature. The timestamping server signs the HASH and the date-time data from an authoritative time source, then return the signed data to the signing tool. Finally, the signing tool write this timestamp data into the PDF file to be signed to complete the timestamp signing. The time source of MeSign timestamping service comes from third reliable timing system
When users use the MeSign service with MeSign App to digitally sign document and sign an electronic contract, MeSign App automatically call MeSign timestamp service, see below right figure, and automatically writes the timestamp signature data together with file signature data and LTV data to complete the digital signature of the PDF file to be signed. The user does not need to manually configure the timestamp service URL and does not need to spend additional money to purchase the timestamp service. Using the MeSign App to complete the digital signature with timestamp service is completely free and fully automatic.
The below screenshot left is showing every MeSign signed document timestamp detail in Adobe Reader, the Timestamp Authority is MeSign Time Stamping Signer. The middle screenshot below is the validity summary from Adobe Reader once you click the MeSign signed document e-signature or e-seal, the documents has been timestamped with Adobe trusted timestamping services, showing that “The signature includes an embedded timestamp’ and the “Signature was validated as of the secure (timestamp) time”(trusted time). The right screenshot below is the digital signature information from Adobe Reader once you click the signature button in the Adobe Reader’s left menu.
Click here to download the MeSign signed sample file, you can check the timestamp information by yourself.