Digital identities overview
A Digital ID is a file pair on your computer that identifies you to other users; typically it is used for online financial transactions, sending secure e-mails and protecting PDF files.
Digital IDs are managed by an industry standard called PKI: the public key infrastructure. A PKI is the set of people, policies, procedures, hardware, and software used in creating, distributing, managing, revoking and using the digital IDs that contain the public/private key pairs used when signing a PDF.
Digital IDs are stored inside certificate files of which there are two types:
- The private Digital ID file
- Contains both your private and your public keys. It must be stored securely and not shared. Typically it is password protected. Its extension is often pfx, but others are possible. Such files must be imported into Power PDF under and .
- The public ID file
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Contains only your public key plus associated data. Common extensions are.p7b, p7c or .cer. This file typically contains:
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Your public key
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Your name and e-mail address
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Expiration date of the key pair
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Serial number of the Digital ID
When the ID came from a Certificate Authority (CA), it also includes
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Name of the issuing CA
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Digital signature of the CA.
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To create a public ID file, go to and select the private ID file you want to use and click Export Certificate.
You can send this public ID file to anyone you trust or need to trust and want to be able to verify your signatures. Sending this file is safe because it cannot be used or misused without the corresponding private key.
About uses of digital identities
Digital IDs are used in the following cases:
- Signed documents
- A signature using a Digital ID lets the recipient know the e-mail or PDF file is from you and lets them check that no changes have been made since the signature was applied. If there are changes, the recipient can see what changed.
- Signed and Certified Documents
- A certified document works the same way, but restrictions on use can be set. With signed and certified documents only the signature is encrypted, not the PDF contents. See Sign/Certify panel and Signing and Certifying Documents.
- Certificate Security
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Digital IDs are used to provide Certificate Security. Do this via the Security panel so that the PDF content is encrypted. This assures recipients that the document was not tampered with during the transit, so you cannot disown authorship of the received content.
About obtaining a digital identity file
Digital ID’s can be created by Power PDF when you create a self-signed certificate, or they can be issued by Certificate Authorities (CA). See Certificates Overview. A self-signed certificate automatically appears in the Security Settings dialog box (called from Security > ID's and Certificates > Manage Digital IDs). Files purchased from a CA or self-created in a different application must be imported by clicking Add ID.