PDF Sign

• Foxit eSign
• Quick PDF Sign
• Sign PDF with a Digital Signature
• Validate Signatures
• Certify a PDF File
• Add a Time Stamp to Digital Signatures and Documents
• Trusted Certificates
• The Digital Signatures Panel
• View Signature Properties

Foxit eSign

Foxit PDF Editor integrates with Foxit eSign, a legally-binding electronic signature service. With a licensed account, you can perform an eSign workflow not only on the Foxit eSign website using a web browser but also within Foxit PDF Editor directly, which allows you to edit your documents and collect signatures with complete ease.

With Foxit eSign in Foxit PDF Editor, after logging in with a licensed account, you can create your own signatures and electronically sign documents by placing the signatures on PDF pages, which is as easy as signing a paper document with a pen. You can also quickly initiate an eSign process to collect signatures from multiple people.

When you electronically sign a PDF within Foxit PDF Editor, the appearance of an applied signature/initials may include information like Signer ID and the date/time when you signed, depending on the settings for your Foxit eSign account. In your Foxit eSign account, you can use a set number of envelopes based on your license plan, and one envelope will be used when you electronically sign a PDF within Foxit PDF Editor. For more information about envelopes and Foxit eSign, you can refer to Foxit eSign Knowledge Base.

Create Your Own Signatures and Sign a PDF

• Open the document you want to sign.
• (Optional) Use the tools in the Foxit eSign tab to add text or symbols to fill your PDF as needed.
• Click the  sign on the signature palette (or click  on the lower right corner of the signature palette and choose Create Signature) in the Foxit eSign tab to create a signature (Full Name) and the corresponding initials. Or you can click Manage Signatures in the Foxit eSign tab and click Add in the pop-up Manage Signatures dialog box to create signatures. (Note: The  sign is displayed when there aren’t any signatures created yet or when there aren’t any initials created for the corresponding signature.) 
• In the Create Signature dialog box:
  • Draw a signature, import a file, copy a snapshot from the clipboard, or type text content to create signatures. (Tip: You can sign your signature on a clean white sheet of paper using a black pen, and scan it to an image file. To create the best signature, it is suggested to scan your signature in monochrome at 600 DPI.)
  • Online > Download Signature/Download Initials to open the Online Signature dialog box, which shows the signatures you have previously saved online. Then select and download the desired signatures as the signature/initials. You can also delete signatures in the dialog box by clicking Delete.   
• Click the Options button to select the options as needed:
  • Convert signature to black & white: the signature will be created in black and white even if the original image is chromatic.
  • Keep original size: selects the option and the signature will be created with the original size. If the signature width/height is greater than the page size, Foxit PDF Editor will zoom it out to a signature with a width of 100 pixels while maintaining the original proportion. The option is only available when the signature is from an imported file or Clipboard. With the option unselected, the signature will be resized and created with a width of 100 pixels while maintaining the original proportion by default.  
  • Discard the signature when program closes: the signature will be discarded the next time you launch Foxit PDF Editor.
  • Require password to use this signature: Specify a password that will be required when users sign the document with the signature. Enter the password again to confirm it.
• Click OK.
• Select your created signature on the signature palette, and then the cursor will be changed into a shape with the appearance preview of the signature.
• Place the cursor to the position you want to sign and click. Or drag a rectangle to define the size and placement. The signature stays selected until you choose another tool. You can place multiple signatures on pages continuously without the need to reselect the same signature.
• Click the signature with the Hand command, and it will be highlighted with a blue rectangle. After adding the signature, do any of the following, if necessary.
  • To resize the signature, drag the small blue square on the lower right corner of the rectangle. After resizing the signature, you can right-click the signature and choose Set Current Size as Default to set the size as default so that Foxit PDF Editor will remember and apply the same size when you add the same signature in the future.
  • To move the signature, drag the rectangle directly to the desired place.
  • Before applying the signature, you can right-click the signature and choose relevant options from the context menu to copy, cut, paste, or delete the signature.
• (Optional) Right-click the signature you added, and select Place on Multiple Pages from the context menu to place the signature to multiple pages.
• Click Apply All Signatures on the ribbon to apply all signatures in the document.

Notes:

• When you have placed signatures/initials that are from the same group of signatures on pages, you need to apply those signatures/initials first if you want to place signatures from another group.
• Once applied, the signatures/initials can no longer be edited or deleted.

Manage Signatures

• Click Manage Signatures in the Foxit eSign tab.
• In the Manage Signatures dialog box, do any of the following:
  • Click Add to create signatures and initials.
  • Click the Edit  or Delete  icon to edit or delete existing signatures.
  • Click the Upload  icon to upload the signature to Foxit eSign server. Please note that Foxit eSign server only saves one group of signatures (full name and initials). If you upload multiple groups of signatures, the latest group will be kept on Foxit eSign server.

Note: If you upload a group of signatures to Foxit eSign server through the Manage Signatures dialog box, the signature/initials saved in your profile in the Foxit eSign website will automatically be changed to the default signatures you set. However, if you make changes to the signature/initials in your profile on the Foxit eSign webpage, the changes will not be synchronized automatically to Foxit eSign in Foxit PDF Editor, and you can download the modified signature/initials through the Online Signature dialog box if needed. 

Initiate an eSign Process in Foxit PDF Editor

To send your documents for eSignatures within Foxit PDF Editor, do the following to initiate an eSign process:

• Open the document you want to send for eSignatures.
• After logging in to your Foxit eSign account, click Request Signature in the Foxit eSign tab.
• A file tab named “Request Signature” is opened in the application window. The current document has been uploaded to the Foxit eSign server and listed in the “Request Signature” file tab. Together with the document, you can add more documents to send for eSignatures.
• Add signers.
• Add the fields to the documents for signers to fill in, and assign the properties to the fields as required.
• Enter the email subject and messages and then send the envelope to the recipients.
• (Optional) You can view all envelopes you have sent in the “Document Status” file tab, which appears when you click Document Status in the Foxit eSign tab.

The process to request eSignatures in Foxit PDF Editor is the same as in the Foxit eSign website, and you can refer to Foxit eSign Knowledge Base for detailed instructions.

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.

• Choose Home/Protect > Fill & Sign. And the Fill & Sign context tab appears on the ribbon.  
• Click  in the signature palette on the ribbon or click  on the lower right corner of the signature palette and choose Create Signature from the drop-down menu. Or you can click Manage Signatures in the Fill & Sign tab and click Add in the pop-up Manage Signatures dialog box to create signatures.
• In the Create Signature dialog box, you can draw a signature, import a file, copy from the clipboard, or type text content to create a signature. Or, click Online to choose a signature from the online signatures you saved before. When you type text to create a signature, you can click Change Style to change the text style for your signature.

TIP: You can sign your signature on a clean white sheet of paper using a black pen, and scan it to an image file. To create the best signature, it is suggested to scan your signature in monochrome at 600 DPI.

• Click Options to specify how to create and use the signature. See also “Options” in Foxit eSign.
• Click OK.
• Select your created signature on the signature palette, and then the cursor will be changed into a shape with the appearance preview of the signature. 
• Place the cursor to the position you want to sign and click. Or drag a rectangle to define the size and placement.
• Place the signature on the document, and adjust its size or position if necessary. See also “Add Signatures” and “Adjust Signatures” in Foxit eSign.
• (Optional) Right-click the signature you added, and select Place on Multiple Pages from the context menu to place the signature to multiple pages.
• You can do one of the following to apply signatures to the document as required:
  • To apply the current signature to the document, right-click the signature, and select Apply Signature from the context menu.
  • To apply all signatures in the document, click Apply All Signatures on the ribbon.
• Upon completion, click Close to close the Fill & Sign context tab.  

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

To manage the created signatures, do the following:

• Click Manage Signatures in the Fill & Sign context tab.
• In the Manage Signatures dialog box, do any of the following:
  • Click Add to create signatures.
  • Click the Edit  or Delete  icon to edit or delete existing signatures.
  • Select a signature and click Move up or Move down to adjust its display order in the signature palette under the Fill & Sign context tab.
  • Select a signature and click Save online to save it to Foxit Web Service. The signatures saved in Foxit Web Service can be downloaded to sign PDF files from within Foxit PDF Reader or Foxit PDF Editor in Windows and Mac.
• Upon completion, click Close to close the Fill & Sign context tab.  

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.

• When you place a digital signature in a PDF file, the Sign Document dialog box pops up. In the Sign Document dialog box, select New ID from the Sign As drop-down list.
• Choose one of the following options, and click Next to continue.
  • My existing digital ID from a file: Choose this option to add the digital ID file if you have got one.
  • A new digital ID I want to create now: Choose this option to create a new self-signed digital ID.
• Do the following based on your selection on the previous step:
  • If you choose to add an existing digital ID file, click Browse to select the digital ID file from your device and input the password. Click Next. Then check your selection, and click Finish to add the selected digital ID file to the list.
  • If you choose to create a new digital ID, follow the steps below.
    • Specify where you would like to store the digital ID file, and click Next.
      • New PKCS#12 digital ID file: Store the digital ID information in a file using the standard PKCS#12 format.
      • Apple Keychain: Store the digital ID in the Apple Keychain, which will be available to other applications on your device.
    • Type your identity information such as name, organization unit, e-mail address, etc. to be used when generating the self-signed certificate. From the Key Algorithm drop-down list, 1024-bit RSA is chosen as the default algorithm, and you can choose 2048-bit RSA for a higher security. From the Use Digital ID for drop-down list, choose whether you want to use the digital ID for digital signature, data encryption, or both.
    • Do one of the following based on your previous selection:
      • If you choose to store the digital ID information in a file, click Next to continue. Then specify the file name, storage location, and password for your new digital ID file, and click Finish.
      • If you choose to store the digital ID in the Apple Keychain, click Finish to complete the settings.  
• When the self-signed digital ID is created successfully, it will be added and kept as selected in the Sign As list. Then you can use it to sign your PDF files. For more information, please refer to “Sign a PDF Document”.

Set Signature Preferences

• Choose File in the Ribbon (or Foxit PDF Editor in the menu bar) > Preferences.
• Select Signature in the Preferences dialog box, and you will find the following options. 
  • Digital Signatures
    • Default Signing Format: Choose a default signing format based on PKCS#7 or CAdES standard. PKCS #7 - Detached is selected by default.  
    • Appearance Styles: Manage the signature appearance templates. For more information about configuring signature styles, please refer to “Create Signature Appearance”.
  • Signing & Verifications
    • Sign the document immediately after the signature is placed: Check this option to sign the document immediately when you place the signature on the document. By default, this option is checked. When it is unchecked, you will need to click Sign Document to apply the signature after placing it on the document. You can still modify the document before applying the signature.
    • Control how and when signatures are verified: click Change Settings to choose options.
      • Verify signatures when the document is opened: If this option is checked, Foxit PDF Editor will verify the signatures when the document is opened, and will display the signature verification results in the Digital Signatures panel. By default, the option is checked.
      • When document has valid but untrusted signatures, prompt to review and trust signers: With the option selected, if the signature (not including certified signatures) is verified as valid but is applied by an untrusted signer with a certificate that doesn’t chain up to a trust anchor, a message box appears in the top-right corner of the application window to inform you the document includes signatures from signers that you haven’t trusted yet. You can click Manage Trust in the message box to trust the signer. More information, please refer to Trusted Certificates.
      • Verification Behavior
        • Require certificate revocation checking to succeed whenever possible during signature verification: Specify whether or not to check the revocation status of certificates while verifying signatures.
        • Use expired timestamps: Uses the secure time provided by the document timestamp or the timestamp embedded in the signature, even if the timestamp’s certificate has expired. The option is selected by default. With the option unselected, the time provided by the expired timestamps will be discarded and the verification time will be the time at which signature was applied or the current time in the system based on your setting on Verification Time.
        • Ignore document validation information: Specify whether to ignore the related certificate revocation information embedded in the document when validating signatures.
      • Verification Time
        You can check the digital signature for validity based on the time when the signature was created, the time provided by the timestamp embedded in the signature, or the current time in your system.
      • Verification Information
        Select an option to specify whether to add verification information to the signed PDF. Ask when verification information is too big is selected by default.
      • Mac Integration
        Specify whether to trust all root certificates in the Mac Certificate Store when validating signatures and certified documents. Checking these options may compromise security. Please make sure that you trust all the root certificates before enabling these features.
  • Saving Settings
    Save signed file as a copy named ‘filename_signed.pdf’: Check this option to save the signed file as a copy named ‘filename_signed.pdf’ after applying the digital signature. When you sign multiple PDF files, you can also specify the file name in Output Options. The file name you specified in Output Options during signing will take precedence over the settings in Signature preferences.
• Click OK to apply the settings.

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.

• When you place a signature in PDF file, the Sign Document dialog box pops up. In the Sign Document dialog box, click Create beside the Appearance Type option.
• In the upper part of the Configure Signature Style dialog box, you can configure the graphic for your signature. You can choose to use no graphic, your handwritten signature, your name, or an image from a file.
  • Name: This tab is displayed by default. If you choose this option, the certificate name that is defined when you create the self-signed digital ID will be shown in the digital signature.
  • Draw: This tab allows you to draw your handwritten signature. When you switch to the Draw tab from any other tabs, the Draw Signature window will pop up automatically. Draw your signature on the pop-up window, and click OK to save your handwritten signature or click Clear to discard it. While in the Draw tab, you can also click Draw Signature to redisplay the Draw Signature window and draw a new signature.
  • Image: Import a file from your local disk as an image. Click Browse to select the file. After importing the image, you can click Opacity to change the opacity. If you need to delete the imported image, click Clear.
  • None: Do not use any image, and only display the information specified in the Configure Text and Configure Logo groups.
• Check the options that you want to appear in the digital signature in the Configure Text group. A signature appearance can include lots of information showing the user’s attributes, including name, reason, location, etc.
• (Optional) In the Text Property group, specify the text direction, font, and size for the text information shown in the digital signature.
  Note: Text Direction options apply to both your common name and configured text (i.e. the information specified in the Configure Text group). You can use different fonts and sizes for your common name and configured text by selecting the desired options in the Common Name and Configure Text group in the Font/Size dialog box.
• By default, Foxit PDF Editor logo will be shown on your digital signature. If you want to change that logo, click Browse in the Configure Logo group to select a desired one.
• In the Title box, input a title for the signature appearance. When you sign a PDF file, you can find the signature by the title in the Appearance Type drop-down list. If you do not specify the title, Foxit PDF Editor will use “Created <date and time the signature was created>” as the title instead.
• Click OK to close the Configure Signature Style dialog box.
• When the new signature style is created successfully, it will be added and kept as selected in the Appearance Type list. Then you can apply that signature style when signing a PDF file. For more information about signing a PDF file, please refer to “Sign a PDF Document”.

Sign a PDF Document

• Click Protect > Sign & Certify > Place Signature.
• Press and hold the mouse button down, and drag to draw a signature field for your signature.
• In the Sign Document dialog box, do the following:
  • Choose a digital ID from the Sign As drop-down menu, and input the password in the Password field. If you can’t find the specified digital ID, you will need to get a certificate from the third-party provider or create a self-signed digital ID. For more information about how to create a self-signed digital ID, please refer to “Create a Self-signed Digital ID”.
  • By default, Foxit PDF Editor will sign a PDF digitally using the standard signature appearance. From the Appearance Type drop-down list, you can choose an existing style or click Create to create a new appearance. For more information about creating signature appearance, please refer to “Create Signature Appearance”.
  • Input the text or select an option from the drop-down list to specify your location and reason to sign the document in the Text For Signing group. Please note that Location and Reason fields are available only when the signature is defined to include the corresponding option in its appearance type. Foxit PDF Editor will remember your location and reason settings for easier use in the future.
  • If you want to lock the document to prevent further editing, check the Lock Document After Signing option.
  • Do any of the following to sign PDF files:
    • To sign the currently opened PDF file, click Sign. Then do one of the following based on your settings in the Signature preferences.
      • If you choose to sign document immediately after a signature is placed in the Signature preferences, the Save As dialog box will pop up. Then specify the location and file name to save the signed document.
      • If you choose to sign later after placing the signature in the Signature preferences, a prompt message will pop up to inform you that you need to sign the document manually. Click OK to continue. (Tip: If you do not want to see the message again, remember to check the Do not show this message again option in the message box.) Before signing the document, you can still adjust the signature. For more information, please refer to “Move, Resize and Delete an Unsigned Signature”. To sign the document manually, click Sign & Certify > Sign Document. Alternatively, you can also select the Hand command first, then click the signature directly, or right-click the signature and choose Sign Document to sign the document. Then specify the location and file name to save the signed document.
    • To sign multiple PDF files, click Apply to Multiple File. In the pop-up Sign Multiple Documents dialog box, do the following:
      • Click Add files, and choose Add Files, Add Folder, or Add Open Files to add files, folders or opened files that you want to sign with the same digital signature.
      • By default, the document will be signed in a sequence as they are ordered in the Sign Multiple Documents dialog box. You can adjust the order of files by its name, modified time, or size by clicking the corresponding column name. Alternatively, drag and drop the file in the list to adjust its order. Select a file and click the Remove button to delete it, if necessary.
      • Click Output Options to specify the output folder and file name for the signed PDF document.
      • Click Sign Immediately. And then Foxit PDF Editor will sign your PDF documents with the same digital signature at the same location as your current document, and saved the signed documents in the folder you specified.

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

• Select the Select Annotation command or the Place Signature command. 
• Right-click the signature and choose Delete from context menu, or press Delete key.

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 the signature first. And right-click the signature with the Hand command and choose Clear Signature. The signature will be cleared and only a blank signature field will be left.
• To replace the signature, click the blank signature field with the Hand command, and create a new signature. See also “Create Signature Appearance”.
• To delete the signature, choose the Select Annotation command or the Place Signature command, right-click the signature field, and choose Delete.

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:

• Choose File in the Ribbon (or Foxit PDF Editor in the menu bar) > Preferences > Signature.
• Click Change Settings in the Signing & Verifications group, and then check the option(s) in Mac Integration group to trust all root certificates in the Mac Certificate Store when validating signatures and certified documents.

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:

• Do one of the following:
  • Choose Protect > Sign & Certify > Trusted Certificates, and double-click the certificate.
  • In the Digital Signatures panel, right-click the signature, choose Show Signature Properties, and then click Show Certificate.
• In the Certificate Viewer dialog box, click Revocation tab to view the revocation information, and click Signer Details to get more information on the source of the revocation information.
• (Optional) If you do not check Require certificate revocation checking to succeed whenever possible during signature verification option in Signature preferences, you can click Check Revocation in the Revocation tab to perform revocation check manually.

Validate Digital Signatures

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

• Choose Protect > Validate to validate all the digital signatures in your PDF document.
• Make sure you have selected the Hand command, then click the digital signature directly to validate the selected signature. Also, you can right-click a digital signature and choose Validate Signature to validate the signature. After validation, you can check the validation status in the pop-up message box, and click Signature Properties to check the details of the signature properties.

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:

• The signature is verified using the secure time provided by a timestamp or at which the signature was applied.
• The signed PDF has not been altered and the certificate has not been revoked or expired.
• The certificate revocation status is embedded in the signed PDF. Embedding certificate revocation information can occur when the document is signed and saved.

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:

• Open the signed document with Foxit PDF Editor.
• In the Digital Signatures panel in the navigation pane, select and expand a signature, and choose Click to view this version. Or right-click the signature in the document pane with the Hand command and choose View Signed Version from the context menu.
• Then this version will be opened in a new tab in the application window, with the title of “filename.pdf-Signed Version”. (Note: If the document has not been modified since the selected signature was applied, a prompt appears saying you are already viewing the version covered by the selected signature.)
• (Optional) Following each signed version in the Digital Signatures panel lists the changes made to the signed version. Clicking on one of the changes will jump to the related area in the document.

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:

• Open the current version you have with Foxit PDF Editor.
• Right-click the desired signature in the document pane with the Hand command (or right-click the signature in the Digital Signatures panel) and choose Compare Signed Version to Current Version from the context menu.
• A PDF document with the comparison result will be automatically created and opened in a new tab within Foxit PDF Editor, and the Compare Files tab appears on the right panel. The results document arranges pages side by side showing the two versions with the changes marked by different icons and colors. The first page and the second page show a summary and details of the comparison results respectively. See also “Compare PDF Files”.
  If the document has not been modified since the selected signature was applied, a prompt appears saying you are already viewing the version covered by the selected signature.

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.

• Click Protect > Sign & Certify > Certify with Visible Signature or Certify without Visible Signature.
• (Optional) If you select Certify with Visible Signature option, press and hold mouse button down, and drag to draw an area on the document where you want the signature to appear.
• Choose a digital ID from the Sign As drop-down list, and input the password in the Password field. If you don’t find the specified digital ID, you need to get a digital ID from a third-party provider or create a self-signed digital ID. See also “Create a Self-signed Digital ID”.
• (Optional) If you choose to certify a PDF document with visible signature, select the appearance type and specify the signing options in the Certify Document dialog box. Please refer to Sign a PDF Document for more information.
• In the Permitted Actions After Certifying item, set authorized actions for your document from the drop-down menu.
• Do one of the following to sign the PDF document:
  • To certify multiple PDF files, click Apply to Multiple Files to add PDF files, and click Sign Immediately to apply the operations. For more information, please refer to “Sign Multiple PDF Files”.
  • To certify the current PDF files, click Sign. And follow the steps in “Sign Current PDF File” to sign and save the certified PDF document.  

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.

• Choose File in the Ribbon (or Foxit PDF Editor in the menu bar) > Preferences > Time Stamp Servers.
• Click New in the Time Stamp Servers Preferences dialog box.
• In the pop-up Time Stamp Server dialog box, input the server name and URL. If credentials are required when using the time stamp server, check This server requires me to log on, and input the user name and password. Then click OK to close the Time Stamp Server dialog box.  
• All the time stamp servers you have configured are listed in the Time Stamp Servers Preferences dialog box. To manage a time stamp server, select it from the list, and do the following:
  • Click Edit to modify the time stamp server settings.
  • Click Delete to remove the selected time stamp server from the list.
  • If only one time stamp server is available in the system, it will be set as default automatically. If multiple time stamp servers have been added, you can select one of them and click Set Default to set it as default. To disable the default time stamp server, click Clear.
• Click OK to apply the settings.

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.

• Set a default time stamp server in the Time Stamp Server preferences. See also “Configure a Time Stamp Server”.
• Sign the document. See also “Sign a PDF Document”.
• You will be prompted with a pop-up Security Warning to ask you to allow connecting to your time stamp server. If you want to skip this prompt message the next time you digitally sign a PDF document with the embedded time stamp, please check the Remember this action for this site for all PDF documents option. Click Allow.
• Then the signature you made has been successfully embedded with a timestamp. When validating the signature, users need to add the time stamp server into the trusted certificate list so that the signature properties will display the date/time in the time stamp server when the document was signed. See also “Trusted Certificates”.

Add a Time Stamp to Documents

• Click Protect > Time Stamp Document.
• If you have configured the default time stamp server, skip to the next step. If not, the Choose Default Timestamp Server dialog box will pop up. Please configure the default time stamp server, and click Next to continue. See also “Configure a Time Stamp Server”.
• Specify a name and location for the signed document. Click Save.
• You will be prompted with a pop-up Security Warning to ask you to allow connecting to your time stamp server. If you want to skip this prompt message the next time you add the time stamp to a PDF document, please check the Remember this action for this site for all PDF documents option. Click Allow.

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:

• Right-click the digital signature, and choose Show Signature Properties.
• In the Signature Properties dialog box, click Show Certificate.
• In the Certificate Viewer dialog box, specify the trust level for the certificate in the Trust tab:
  • Use this certificate as a trusted root: Use the certificate as a trusted root, and trust all certificates issued by that certificate authority. Once you make a certificate a trust anchor, revocation checking will not be performed on it.
  • Validating Signatures or Validating Certified Documents: Trust the certificate when validating signatures or certified documents.
• Click Add to Trusted Certificates, and confirm your operation.

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

• If a time stamp is added in the document, go to the Digital Signatures panel in the navigation pane, right-click the timestamp signature, and choose Show Signature Properties. In the pop-up Signature Properties dialog box, click Show Certificate. See also “Add a trusted digital certificate to the Trust Certificates list”.
• If a time stamp is added to a digital signature, right-click the signature field in the document or right-click the signature in the Digital Signatures panel, and choose Show Signature Properties from the context menu. Click Advanced Properties in the lower-left corner of the pop-up Signature Properties dialog box, which opens the Advanced Signature Properties dialog box. Then click Show Certificate. See also Add a trusted digital certificate to the Trust Certificates list.

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:

• Choose View in the menu bar > Navigation Panels > Digital Signatures.
• Click the Digital Signatures button  in the Navigation panel.

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.

• Select the Hand command.
• Right-click the signature field (or right-click the signature in the Digital Signatures panel) and choose Show Signature Properties from context menu.
• In the Signature Properties dialog box, you can get the information as follows:
  • Signed by – Show the signers that sign the document.
  • Reason – Display the reason why the user signs the document.
  • Date – Show the date and time when the document is signed.
  • Location - Show the location where the document is signed, which is optionally added by the signer when placing the signature.
  • Validity Summary - Check whether the document was modified after it was signed, and other information.
  • Show Certificate – Click it to open the Certificate Viewer dialog box. Click Show Certificate in the Certificate Viewer dialog box to view the details of the signature certificate and add the certificate to the Trusted Certificates list. See also “Add a trusted digital certificate to the Trust Certificates list”.
  • Signer’s Contact Information – Display the contact information specified by the signer when signing the document, if any.
  • Advanced Properties – Click it to open the Advanced Signature Properties dialog box where you can view the details about the signature and the embedded time stamp (if any). For a signature embedded with a time stamp, you can click Show Certificate in the Advanced Signature Properties dialog box to add the time stamp server to the Trusted Certificates list. See also “Add a trusted digital certificate to the Trust Certificates list”.