Frequently asked questions
Are the signatures the document already had lost?
No, and that is what sets us apart. We sign by appending to the end of the file instead of rewriting it, so earlier signatures still match their bytes and stay valid. It is exactly what almost every free tool breaks.
Do my certificate and its password leave my device?
No. The certificate is opened and used inside your browser, and the private key is discarded when it finishes. You can check it by going offline: the tool works just the same, because there is nothing to send.
Does it work with a government-issued certificate?
Yes, as long as you have it as a .p12 or .pfx file. If your certificate is installed in the system, you first need to export it to that format from your keychain or certificate manager.
Can I use a certificate I created myself?
Cryptographically yes: it proves the document hasn't been altered since you signed it. But since nobody external vouches for your identity, whoever receives it will see «unknown issuer». Official paperwork needs a certificate from an accredited authority.