Digital IDs include a private key that you safeguard and a
public key (certificate) that you share.
A digital
ID is like a driver’s license or passport. It proves your
identity to people and institutions that you communicate with electronically.
A digital ID usually contains your name and email address, the name
of the company that issued your digital ID, a serial number, and
an expiration date.
Digital IDs contain two keys: the public key locks, or encrypts,
data; the private key unlocks, or decrypts, that data. When you
sign PDF documents, you use the private key to apply your digital
signature. You distribute the certificate that contains
your public key and other identifying information to those who need
to validate your signature, verify your identity, or encrypt information
for you. Only your private key can unlock information that was encrypted
using your certificate, so be sure to store your digital ID in a
safe place.
You must have a digital ID to sign, certify, and apply certificate
encryption to PDFs. You can get a digital ID from a third-party
provider, or you can create a self-signed digital ID. Self-signed
digital IDs may be adequate for many situations. However, to prove
your identity in most business transactions, you may need a digital
ID from a trusted third-party provider, called a certificate
authority. Because the certificate authority is responsible
for verifying your identity to others, choose one that is trusted
by major companies doing business on the Internet. See the Adobe
website for information about Adobe security partners that offer
digital IDs and other security solutions.
You can have multiple digital IDs that you use for different
purposes, particularly if you sign documents in different roles
or using different certification methods. Digital IDs are usually
password protected and can be stored on your computer in PKCS #12
file format, on a smart card or hardware token, in the Windows certificate
store, or on a signing server (for roaming IDs). Acrobat includes a default signature
handler that can access digital IDs from any of these following locations.
(You must register the digital ID in Acrobat for
it to be available for use.)
