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PDF Sign

Quick PDF Sign

Quick PDF Sign enables you to create your self-signed signatures (ink signatures) and add the signature to the pages directly.

To create your own signature and sign a PDF, follow these steps.

Note: Once applied, the signature can no longer be edited or deleted.

To manage the created signatures, do the following:

Sign PDF with a Digital Signature

A digital signature acts as a traditional handwritten signature that can be used to authenticate the identity of a user as well as the document content. It stores information about the signer along with the date, time, and state of the document when it was signed.

Digital ID

About Digital ID

Digital ID is the identity of a person/organization, which contains your name, Email address, a serial number, an expiration date, and the name of the company. A digital ID contains two keys, one is a public key (certificate) that is used to encrypt or lock data, and the other is a private key that is used to decrypt or unlock data that is encrypted.

You can distribute the certificate that contains the public key and other identifying information to those people who need to use it to verify your identity, validate your signature, or encrypt a document for you. Only your private key can unlock information that was encrypted using your certificate, so make sure to store your digital ID in a safe place.

You can not only obtain a digital ID from a trusted third-party provider called a Certificate Authority (CA) but also create a self-signed digital ID with Foxit PDF Editor. Digital IDs are usually protected by password; you can store it on a computer in PKCS#12 file format, or in the Apple Keychain. All the digital IDs available on the computer are listed in the Digital IDs window. You can choose Protect > Sign & Certify > Digital IDs to check the digital IDs list. In the Digital IDs window, you can also view the certificate details, refresh the ID list, add or remove a digital ID, and export a digital ID to an FDF, PKCS, or CER file.

Create a Self-signed Digital ID

To create a self-signed digital ID when signing a PDF file, please follow the steps below.

Set Signature Preferences

Create Signature Appearance

A digital signature can include an image of your handwritten signature, a company logo, date, reason for signing, etc. Before signing a PDF document, you can configure the signature appearances in the Signature preferences. The options in the Signature preferences also allow you to manage all the created signature styles. For more information, please refer to “Set Signature Preferences”. Foxit PDF Editor also allows you to create new signature appearance when placing a digital signature. To create a new signature appearance when signing a document, please follow the steps below.

Sign a PDF Document

Move, Resize and Delete an Unsigned Signature

You can move, resize and delete signatures before signing the document, but you aren’t allowed to change certificate and appearance of certificate.

Move a Signature

Select the Select Annotation command or the Place Signature command, put the pointer over the signature, click and drag the signature to another place you like.

Resize a Signature

Select the Select Annotation command or the Place Signature command, and drag any handle along the border to resize the signature.

Delete a Signature

Note: If you have checked the Locked option in the Signature Properties dialog box, the operations to the signature above are not available.

Modify a Signed Signature

The signer who have the digital ID for signing installed can modify the signature after signing the document.

Validate Signatures

Signature validity is determined by checking the authenticity of the signature's digital ID certificate status and document integrity.

Set Signature Verification Preferences

By default, Foxit PDF Editor will verify digital signatures when the document is opened, and will check the certificate revocation status while verifying signatures. If you want to change the setting, please choose File in the Ribbon (or Foxit PDF Editor in the menu bar) > Preferences > Signature, and uncheck the corresponding option in the Signing & Verifications group. For more information, please refer to “Set Signature Preferences”. 

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:

Tip: You can specify the trust level for a specific certificate in Foxit PDF Editor 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 Certificate Revocation Status

By default, Foxit PDF Editor will check the certificate revocation status while validating a signature if the certificate used to sign a PDF file chains up to a certificate designated as a trusted anchor. Revocation checks are performed based on the revocation information embedded in the digitally signed PDF document, the digital signature, or the Certificate Revocation List (CRL). To view the certificate revocation information, please do the following:

Validate Digital Signatures

To validate digital signatures, please do one of the following:

Long-term Signature Validation

Many business or other practical applications need digitally-signed documents to be verifiable for months or years after signing. However, the signed document can be no longer verifiable if the signer’s certificate has expired or been revoked, or with some other reasons. To reduce chances for error or fraud, Long Term Validation (LTV) is introduced for digital signatures in PDF, which is in compliance with Part 4 of the ETSI TS 102778-4 PDF Advanced Electronic Signatures (PAdES) standard.

When LTV is enabled, the document can be validated at any time in the future. To achieve long-term validation, the following are required:

From the Digital Signatures panel, you can check whether the signature is LTV enabled or not after validation. In some cases, the certificate revocation information may not be embedded successfully in the document when you sign the document (especially when you are offline) and you will be informed the signature is not LTV enabled. You can right-click the signature and choose Add verification information to add the information to the signature.

Note: To use secure time for verification, after clicking Change Settings for Singing & Verifications in the Signature preferences, select the Time at which the signature was created, or Secure time (timestamp) embedded in the signature if a trusted timestamp is embedded.

View Signed Versions of a Digitally Signed PDF

A signed version will be automatically saved each time you sign a PDF with a digital signature. If a digitally signed document was modified, you can still view the signed version without the modification. For a document digitally signed several times, you can view each signed version without the changes made after each signature was applied. All signed versions along with their corresponding digital signatures are listed in the Digital Signatures panel.

To view a signed version of a digitally signed PDF, do as the following:

Compare Versions of a Digitally Signed Document

For a digitally signed document (which might have been signed several times), you can view the differences (if any) between a signed version and the current version you have.

To compare a signed document with the current version, do as the following:

Certify a PDF File

Foxit PDF Editor allows a PDF document author to certify his/her own PDF document to indicate the approval of its content.

Add a Time Stamp to Digital Signatures and Documents

Time stamps are used to specify the date and time you signed a document. A trusted time stamp proves that the contents of your PDFs existed at a point-in-time and have not changed since then. Foxit PDF Editor allows you to add a trusted time stamp to digital signatures or documents.

Configure a Time Stamp Server

To add a time stamp to digital signatures or documents, you need to configure a default time stamp server first.

Add a Time Stamp to Digital Signatures

To add a time stamp to digital signatures, a default time stamp server is required before you make the digital signature. If you have configured a default time stamp server and added it to your trusted certificate list, the time stamp will be embedded with the signature, and the signature properties will show the date/time in the time stamp server when you signed the document; otherwise, the signature properties will display the local date/time of the computer.

Add a Time Stamp to Documents

Trusted Certificates

When you validate or view properties of a digital signature or an embedded timestamp, the validity status may display “unknown” or “could not be verified”. You need to add the certificate that issued your digital IDs as well as the time stamp server to the Trusted Certificates list.

To add a trusted digital certificate to the Trust Certificates list, please do the following:

To add a trusted time stamp server to the Trusted Certificates list, please do either of the following:

To check all the trusted certificates, choose Protect > Sign & Certify > Trusted Certificates. In the Trust Certificates window, you can manage all the trusted certificates, including adding & exporting a certificate, viewing certificate details, deleting a certificate, and specifying the trust level for a certificate.

The Digital Signatures Panel

The Digital Signatures panel shows information about each signature and time stamp in the document as well as the change history of the document since the first signature. To open the Digital Signatures panel, do one of the following:

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.