DigiSigner is a freeware program which lets you embed validated digital signatures into standard PDF documents. It’s Java based, and you’ll need access to some legitimate key technology such as a smartcard dongle or Windows key store certificate in order to make it properly pukka.
Of course the really important people like banks and lawyers won’t accept it, but when have the Luddites ever got on board with nascent technology without a fight?
PDF signing using certificates DigiSigner uses standard X.509 certificates to sign your PDFs. It produces real digital signatures that secure your documents and not just embeds pictures in your documents. Signature verification Signature verification DigiSigner validates digital signatures for you to ensure that your document was not changed or damaged. DigiSigner informs you who signed the document and reports other details.