A timestamp is a trusted service that provides evidence that specific digital data existed at a particular point in time. The timestamping service, provided by SwissSign as a Trust Service Provider, applies a trusted time value and a digital signature to the data (or its hash), thereby ensuring the integrity and proving the existence of the data at that specific moment.

The SwissSign timestamping service complies with the requirements of Swiss law (ZertES) and applicable standards for trusted timestamping services.

Digital timestamps are primarily used for archiving documents with verifiable timing and for timestamp business documents such as contracts. Furthermore, under Swiss law (ZertES) a qualified electronic signature is legally equivalent to a handwritten signature only when it is accompanied by a ‘qualified’ timestamp.

SwissSign timestamps can be used into workflow and archiving solutions to provide an independent, trusted record of the exact time at which a document or data record existed. While every electronic signature includes a local system timestamp, an externally authenticated timestamp offers a higher level of trust by verifying the time through a trusted third party.

This enables organizations to demonstrate that a document or data record existed at a certain point in time and that it has remained unchanged since it was timestamped, thereby ensuring its integrity and supporting long-term evidential value.

Typical use cases include compliance with legal and regulatory requirements, such as the Swiss Business Records Ordinance (AccO/GebüV), corporate governance and compliance frameworks like SOX and Basel II, and industry-specific quality standards such as Good Manufacturing Practice (GMP).

A digital timestamp is, in technical terms, a cryptographic signature created by a trusted provider that binds a document to a verifiable point in time. This timestamp is generated by a Timestamping Authority (TSA) in accordance with RFC 3161, the standard protocol for trusted timestamping.

Under RFC 3161, the timestamp request contains only the cryptographic hash of the document rather than the document itself. The TSA signs this hash together with the trusted time, creating a timestamp token. Because only the hash is processed, the TSA has no access to or knowledge of the document's contents, ensuring both confidentiality and privacy while providing verifiable proof of the document's existence and integrity at the recorded time.

Access to the SwissSign Timestamping Service is now protected by HTTP Basic Authentication. This authentication mechanism ensures that only authorized customers can use the service and helps prevent unauthorized or excessive use.

Please select the option below that best describes your situation:

I'm already a SwissSign customer

If you have an active timestamping service contract but are unable to authenticate or have lost your credentials, please contact our support team. We will assist you in restoring access.

I'm not a SwissSign customer yet

If you do not yet have access to the SwissSign Timestamping Service, we would be happy to provide you with information about the service and a non-binding offer. Once your subscription has been set up, you will receive the authentication credentials required to access the service. Please contact us here to get started.

For more information, click here.

The reason for this is the adaptation of the timestamping service to the new security requirements and the resulting increase in the size of the response to the Adobe program by a few bytes. During the signing process, Adobe Acrobat reserves a fixed amount of space in the PDF for the timestamp token before requesting it from the TSA. If the returned timestamp exceeds this reserved size, the signing operation fails. The issue can be resolved by increasing the iSize registry setting, which determines the amount of space Acrobat reserves for timestamp responses.

The following patch for Adobe Reader DC serves as an example. Please save the following text as the file ‘fix_adobe.reg’ and double-click to make the change to the registry. It is advisable to back up the registry beforehand. Remember that the registry file is always specific to the Adobe version and, therefore, the text may need to be modified. E.g. may the part below that reads «Adobe Reader» be replaced by «Adobe Acrobat».

For Adobe Reader:

Windows Registry Editor Version 5.00

[HKEY_CURRENT_USER\Software\Adobe\Acrobat Reader\DC\Security\cASPKI\cAdobe_TSPProvider]

"iSize"=dword:00002800

For Adobe Acrobat Pro:

Windows Registry Editor Version 5.00

[HKEY_CURRENT_USER\Software\Adobe\Adobe Acrobat\DC\Security\cASPKI\cAdobe_TSPProvider]

"iSize"=dword:00002800