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What is Public-Key Cryptography?

Public-Key Cryptography, which is also known as asymmetric cryptography, is a system that uses pairs of keys to encrypt and authenticate information. One key in the pair is a public key which can, as the name suggests, be distributed widely without impacting security. The second » Continue Reading.

Sign a PDF in Adobe Acrobat Reader

This how-to will show you how to sign a PDF document in Adobe Acrobat Reader with a document signing certificate from These instructions were tested with a document signing certificate installed in slot 1a of a YubiKey FIPS, in Acrobat Reader 2019.021.20056, on Windows » Continue Reading.

Use Your YubiKey for S/MIME Email in Thunderbird

Mozilla Thunderbird users may have noticed that S/MIME certificates installed on a YubiKey hardware token are not immediately available for use in Thunderbird. Even though the YubiKey’s smart card features are supported by the underlying OS on both Windows and macOS, Thunderbird requires an additional » Continue Reading. Joins Adobe Approved Trust List (AATL)

Digitally Certify and Sign PDFs, a public certificate authority (CA) and voting member of the CA/Browser forum, is pleased to announce that it has been added to the Adobe Approved Trust List (AATL). The AATL is comprised of CAs that meet Adobe’s stringent assurance » Continue Reading.

Install an S/MIME Certificate on your YubiKey’s document signing and client authentication certificates are delivered on a secure YubiKey FIPS USB hardware token. To protect our customers’ information against the possible loss of their YubiKey, these certificates offer email signing but cannot be used for encryption or decryption. However, your certificate » Continue Reading.

Activate Your Personal Business Certificate

How to Activate your Personal Business Document Signing and S/MIME Certificate Now that you have received your PBDSS Certificate from, you’re probably looking at the USB token in the box and wondering, “what do I do now?” Here are a few easy steps to » Continue Reading.

October 2019 Security Roundup

  Welcome to the October 2019 edition of’s Security Roundup, an end-of-month digest where we highlight important developments in the field of SSL/TLS, digital certificates, and digital security. On the browser front this month, Google has decided to start blocking mixed content in Chrome, » Continue Reading.

Which Code Signing Certificate Do I Need? EV or OV?

  You probably already know that a code signing certificate from will assure users that your software is from a known and trusted developer, free from unauthorized modifications and malware, and safe to install, but which code signing certificate should you buy? offers » Continue Reading.