1. Where can I order the full version of the PdfCrypter software?

2. Can I create PDF files with the PdfCrypter?

3. What is a certificate?

4. Where can I obtain a certificate?

5. What are private and public keys?

6. How can the trustworthiness of different certificates be assessed?

7. How do I transmit my public key?

Question: Where can I order the full version of the PdfCrypter software?

Answer: You can order the full version of the PdfCrypter software from our shop or your software dealer. Delivery is via download, i.e. you will be sent an activation code by e-mail. You may also order the software on CD-ROM. This, however, entails additional costs. If you do not want to order via the internet, you can also fax your order to us or simply give us a call.

Question: Can I create PDF files with the PdfCrypter?

Answer: No, the PdfCrypter is a tool for subsequently securing and encrypting PDF documents. Special software is required to create PDF files.

[top]

Question: What is a certificate?

Answer: A digital certificate serves to verify, beyond doubt, the identity of its owner. As well as the name of the owner, it also contains the latter’s public key, a serial number, the duration of validity and the name of the issuer.

To ensure the unequivocal assignment of a certificate to a person, the certificate must be issued by a trustworthy organization or authority which, in turn, guarantees that the certificate does indeed belong to a particular person.

Question: Where can I obtain a certificate?

Answer: There are a number of ways of obtaining a certificate

Create a self-signed certificate:
To create your own certificate using the PdfCrypter, select the tab 'Own identity' under Options – Preferences. Press the button 'Add' and select 'Create new'. A wizard takes you through all the necessary steps to create and save a certificate using Windows.

Request a certificate within your company:
Microsoft Windows Server 2003 provides a PKI (Public Key Infrastructure) for creating certificates. This can normally be done via the Intranet. Contact your network administrator for further details.

Certification service provider:
There are a number of certification service providers around the world (Certification Authority or CA for short).

[top]

Question: What are private and public keys?

Answer: An asymmetric procedure is used in the case of encryption with certificate security. This means that encryption and decryption are only possible with two different keys: the private and the public key.

An example:
To securely exchange documents with a recipient, you firstly require the recipient’s and your own certificate (own identity). The document can now be encrypted using the recipient’s public key and then sent to the recipient. Since this document was encrypted using the latter’s public key, only this recipient is able to open the document using his or her private key.

Question: How can the trustworthiness of different certificates be assessed?

Answer: Trustworthiness of certificates

To ensure the unequivocal assignment of a certificate to a person, the certificate must be issued and signed by a trustworthy organization or authority which, in turn, guarantees that the certificate does indeed belong to a particular person.

When documents are exchanged within an organization, this can be done by the organization itself, as all staff can regard the company as being trustworthy. Microsoft Windows Server 2003 already provides a PKI (Public Key Infrastructure) for creating certificates.

In the case of communication outside of an organization, only a superordinate certification authority is able to guarantee the trustworthiness of a certificate on the basis of its digital signature.

For a certificate to be regarded as valid, one must therefore have confidence in the certification authority itself. For this reason, many certification authorities have already been classed as trustworthy in web browsers:

Internet Explorer: Tools --> Internet options --> Content --> Certificates --> Trustworthy certificate authorities

Mozilla Firefox: Tools --> Settings --> Extended --> Certificates --> Manage certificates

Of course, you and the recipient of your document can also create self-signed certificates in this way.

Question: How do I transmit my public key?

Answer: There are two ways of transmitting your public key (your certificate) to a recipient.

Transmission from PdfCrypter
Firstly set up a profile with certificate security. One or more recipients are specified in this profile (recipient-based encryption). Then select this profile in the main window of the PdfCrypter. The recipients specified in this profile are listed below the profile selection. Right mouse click on a recipient who you wish to transmit your public key to and then select the entry 'Own public key' in the open context menu followed by the sub-entry, 'Send via e-mail'. A Windows dialog field then opens in which you must firstly select the e-mail program to be used. Acknowledge this by pressing 'OK'. A finished e-mail with sample text opens which already has your public key attached as a ZIP file.

Note: This option is only available if you have already saved your own identity in the global program settings.

Transmission from Windows Certificate Storage
Certificates can also be directly exported and sent from the Windows Certificate Storage. To do this, open Internet options in the system control (or via the Internet Explorer Tools --> Internet options) --> Content --> Certificates --> Own certificates. Here you will see all the certificates issued to you. Select the certificate whose public key you would like to transmit and then select 'Export'. Follow the instructions given by Windows on the monitor and save your key in a location of your choice for subsequent transmission.

Important: As part of the Windows export dialog, you will be asked whether the private key should also be exported as well. For the purpose of transmission this question must be answered with 'No'!