Fluid PDF - Version 3 Digital sign PDF documents with PKI and Biometric Signature or Fingerprints. It enables document binding that secures PDF from any tempering. For PKI signature, Fluid PDF supports the use of file pfx certificates or USB tokens that is supplied by our Certificate Authority partner Netrust Pte Ltd. For Biometric signature, Fluid PDF fully adopts the methodology of our partner Topaz Systems. It makes use of Topaz's electronic signature/fingerprint. PDF document is now more easily protected with Fluid PDF. You can encrypt and decrypt a PDF document with options of password as well as biometric fingerprint. With the encryption, you can set digital permissions onto the document with ease. The digital permissions can be set both in native permissions or generic PDF permissions in Fluid PDF.