How does it work?

This is a too big topic to cover. Read more in the link list at the home page.


  • Free of charge (if you do not use root certificates).
  • Projects have been around for a long time.
  • Many contributors and users.


  • It's mainly focused on sending and encrypting email, rather than everyday document management in the companies.
  • It's complicated to install and to use for the common user. Multiple signatures with series of approvers and an audit trail are usually not supported.
  • Creating and publishing certificates is difficult (Web of trust, CA) and requires users to understand many detailed concepts, as well as configure and install multiple tools.
  • It requires online connection to external servers, to ensure validity of the signature.
  • It's difficult to investigate and show the "digital hierarchical trust" during an audit. Customized signature with graphical representation is not supported.