Adobe 22020807 User Guide - Page 271

USING ACROBAT 9 PRO 265 Digital signatures Customizing signature properties using seed values Seed values offer additional control to document authors by letting them specify which choices a user can make when signing a document. By applying seed values to signature fields in unsigned PDFs, authors can customize options, and automate tasks. They can also specify signature requirements for items such as certificates and timestamp servers. For more information about customizing signatures using seed values, see the Digital Signature User Guide (PDF) available at www.adobe.com/go/learn_acr_security_en. Validating signatures Checking the validity of a signature When signatures are validated, an icon appears in the document message bar to indicate the signature status. Further details about the status appear in the Signatures panel and in the Signature Properties dialog box. Third-party signature handlers can provide alternate methods of validating signatures. Check the documentation included with your third-party digital ID. Important: To ensure that signatures are valid when you open a PDF and that all verification details appear with the signature, set your verification preferences in advance. (See "Set signature verification preferences" on page 267.) If the signature status is unknown or unverified, validate the signature manually to determine the problem and possible solution. If the signature status is invalid, contact the signer about the problem. For more information about signature warnings and valid and invalid signatures, see the Digital Signature User Guide (PDF) at www.adobe.com/go/learn_acr_security_en. More Help topics "Verify information on a certificate" on page 238 "Get certificates from other users" on page 235 Validate a signature manually You can assess the validity of a digital signature by checking the signature properties. 1 Set your signature verification preferences. For more information, see "Set signature verification preferences" on page 267. 2 Open the PDF containing the signature, right-click the signature, and then choose Validate Signature. The Signature Validation Status describes the validity of the signature. 3 Click Signature Properties, and do the following: • If the status is unknown, click the Signer tab, and then click Show Certificate to view the details of the certificate. If you're working with self-signed digital IDs, confirm that the certificate details are valid. If the certificate isn't valid, request a valid certificate from the signer. Click OK. • Click the Date/Time tab to verify the timestamp, if needed. • Click the Legal tab to learn more about the legal restrictions of the signature. In the Legal tab, click View Document Integrity Properties to check if it contains items that could alter its appearance. If the document was modified after it was signed, check the signed version of the document and compare it to the current version. Last updated 9/30/2011