I guess you confuse terminology. It seems to me that you encrypted PDF with a certificate encryption, not signed it. Is this correct? I am not quite sure what you mean by "run a PDF". It seems to me that you mean "open PDF". Is this correct? If my assumptions are correct, then continue reading.
You can open a pdf encrypted with certificate encryption onlt on a computer that has a Digital ID (with private key) that corresponds to one of the certificates (with public key only), included in the recipients section of the encryption block. The whole purpose of the certificate encryption is to limit who may open the document. At the encryption step the document's author selects the list of possible recipients by providing certificates with their public keys. Only the recipient who has a Digital ID installed on the system with the private key that corresponds to one of the certificates with the public key included in the recipients section of the encryption block may open this PDF.
If you encrypt PDF with the certificate encryption you need to do two things. First, you need to collect from your possible recipients tehir certificates with the public key (public key is not secret, only private key is). Second, in Acrobat UI when you get to "Select recipients" step, you browse to the locations where you stored possible recipients public-key certificates (the "Browse" button) and select those who you want to be able to open this PDF. If some certificates are stored on-line or in common storage directories (like LDAP) you can search for them using the "Search" button.
You may want to learn more about encryption by reading Acrobat documentation, including books (like "Acrobat in classroom") about Acrobat..
Yes you guessed my terminology rightly.
But still am confused how to open my digitally encrypted pdf file on my recipients's computers only.
Please guide me step by step.
From starting i.e from making a digital id,or after this step only.
If you Google "encrypt pdf with certificate in Acrobat" you will get quite detailed instructions. You may want to read more than one post to learn more. Keep in mind that:
1. When you encypt a PDF with certificate encryption you need to have certificates with public keys for all possible recipients as files on your computer. You also need to have your own certificate with private key on your computer, so that you can open your PDF after it has been encrypted.
2. Each of the possible recipients must have his/her Digital ID with private key installed in their copy of Acrobat or Adobe Reader. In Acrobat X you install a Digital ID by going to Tools->Sign&Certify->More Sign & Certify->Security Settings. In Acrobat XI you got to Edit->Preferences->Signatures->Identities & Trusted Certificates. In the corresponding dialog select AddID and follow instructions in the dialog for "My existing Digital ID for" "A file".
3. Usually you do not make a digital ID yourself. You buy digital IDs from reputable issures, like VeriSign. You can create a self-signed Digital ID in Acrobat but they are much less secure. To make a Digital ID you go again to the same dialog as in #2 and select AddID and then select "A new Digital ID I want to create" and follow instructions. Each of your recipients should do the same on their machines. Then each of them should select their Digital ID and select "Export" to export their certificate with a public key. Then they need to send the exported certificate to you, so that you can add it to the recipients' list in the process of encryption.
Thanks for your reply .You are great
I got what i wanted to know
Is there any other way from protecting users to prevent users from forwarding my pdf file to others??
Please help me out of this too.