When encrypting a PDF wirth a digital certificate, there is no way around the requirement for a password. The purpose of encrypting a PDF with a certificate is to ensure that the PDF can only be opened by specific users (those users whose public keys were used in the encryption) These users must authenticate (supply password for their private key) to the document to view it. If there was no authentication, then it defeats one of the benefits of certificate encryption.
If you do not want to have authenitcation, you have two possibilities...
1) Use password encryption (permissions password, without a document open password) on the document to limit what can be done to the document while still allowing anyone to open it without entering a password.
2) Use LiveCycle ES2 Rights Management to encrypt the documents with "anonymous" user policies. This is a policy that will encrypt the document and restrict permission on the document, but does not require user authenttication to view the document. This method is much more secure than password based encryption.
Hope this helps.
thank you for your help. I will try to convince the customer that passwords are nessecary. After all its his confidential data that has to be secured ...