Order of operations

Any combination of encrypting, certifying, and applying usage rights to the same document must occur in the following order. These services must be invoked within a short-lived process:

1. Apply encryption (Encryption service) or apply a policy (Rights Management service) to a document before you digitally sign the document (Signature service). A digital signature records the state of the file at the time of signing. Encrypting the document or applying a policy after you apply a signature changes the bytes in the file, causing the signature to appear invalid.

2. Certify a PDF document (Signature service) before you set usage rights (Reader Extensions service). If you certify a document after you apply usage rights, it invalidates the usage rights signature, therefore removing the usage rights from the document.

3. Digitally sign a PDF document (Signature service) after you set usage rights. Signing a PDF document after applying usage rights does not invalidate the usage rights signature.

   Also, you cannot encrypt a PDF document and apply a policy to the same PDF document, and you cannot apply a policy to an encrypted PDF document.

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