Signature validity is determined by checking the authenticity of the signature’s digital ID certificate status and document integrity. Depending on how you have configured your application, validation may occur automatically.

Set Signature Verification Preference

By default, Foxit Reader will verify signatures when the document is opened. If you want to change the setting, please go to File > Preferences > Signature, and uncheck the Verify signatures when the document is opened option in Signing & Verifications group.

Set the Trust Level of a Certificate

The signature of a certified or signed document is valid if you and the signer have a trust relationship. The trust level of the certificate indicates the actions for which you trust the signer.

To set the trust level:

·  Choose File > Preferences > Signature.

·   Check the option(s) in Windows Integration group to trust all root certificates in the Windows Certificate Store when validating signatures and certified documents.

Tip: You can specify the trust level for a specific certificate in Foxit Reader Trusted Certificates list while adding and managing the trusted certificate. Please refer to Add Trusted Certificates and Manage Trusted Certificates for more information. If you configure different settings for the same certificate, settings with higher permissions will prevail. Remember that checking trust options may compromise security. Please make sure that you trust all the root certificates before enabling the features.

Check the validity of a signature

By default, Foxit Reader verifies signatures when the document is opened. An icon appears on the left top of Signature Validation Status message box to indicate the signature status. The signature state appears in the Signature Panel.

• The question mark icon  indicates the signature is not validated.

• The check mark iconindicates that the signature is valid.

• The iconindicates that the signature is invalid. The document has been altered or corrupted since the signature was applied.

• The caution triangle icon  indicates the document was modified after signature was added; however, the signature is valid.

• The iconindicates the signature validity is unknown because the signer’s certificate isn’t in your list of trusted identities.

Validate a signature

1.  Open the PDF containing the signature, do one of the followings:

• Choose Protect  > Validate.

• Right-click the signature with Hand command, choose Validate Signature from context menu.

• Select Hand command on toolbar and click the signature.

2.  Pop-up a Signature Validation Status message box which describes the validity of signature.

View Signature Properties

Signature Properties dialog box provides basic information about the signature, including the signer, reason, date, location validity summary and details of certificate, etc.

1.   Select the hand command.

2.   Right-click the signature, and choose Show Signature Properties from context menu.

3.   In Signature Properties dialog box, you can get the information as follows:

• Signed by – shows the signers that sign the document.

• Reason – displays the reason that you create the signature.

• Date – shows the date time when you signed the document.

• Location - shows which page the signature is located on.

• Validity Summary - checks whether the document was modified after it was signed, and other information.

• Show Certificate – click it to show the details of certificate, such as the validity of certificate, certificate path, etc.

                                         Signature Properties Dialog Box

Note: If the status is unknown, click Show Certificate in the Signature Properties dialog box, then click Show Certificate in the pop-up Certificate Viewer dialog box to view the details of the certificate. Check whether the certificate has been included in your list of trusted identities. If your certificate is not trusted, click Install Certificate to install it to the trusted Windows Certificate Store. If you use a self-signed digital ID, confirm that the certificate details are valid. If the certificate isn’t valid, a valid certificate from signer is requested.