A digital certificate is a secure digital identity that certifies
the identity of the holder. Issued by a Certification Authority,
it typically contains a user's name, public key, and related information.
A digital certificate is tamper-proof and cannot be forged, and
is signed by the private key of the Certification Authority which
The act of disguising information through the use of a key so that
it cannot be understood by an unauthorized person.
A developing standard for security at the network or packet processing
layer of network communication. Is especially useful for implementing
virtual private networks and remote user access through dial-up
When used in the context of cryptography, a series of random numbers
used by a cryptographic algorithm to transform plaintext data into
encrypted data, and vice versa.
A pair of digital keys - one public and one private - used for encrypting
and signing digital information.
A cryptographic key known only to the user, employed in public key
cryptography in decrypting or signing information. One half of a
The other half of a key pair, a public key is held in a digital
certificate. Public keys are usually published in a directory. Any
public key can encrypt information; however, data encrypted with
a specific public key can only be decrypted by the corresponding
private key, which the key owner keeps secret. A public key can
also be used to verify the authenticity of a digital signature.
Key Infrastructure (PKI)
A set of policies, processes, and technologies used to verify, enrol
and certify users of a security application. A PKI uses public key
cryptography and key certification practices to secure communications.
High level personal/professional digital identity assurance supporting
legally valid digital signatures.
A person or organization responsible for the identification and
authentication of an applicant for a digital certificate. An RA
does not issue or sign certificates.
A device that is often the same size as a credit card but that is
“smart” enough to hold its own data and applications and do its
own processing. Smart cards can be used to store personal information,
hold digital cash or prove identity.
A timestamp is the digital proof that objectively enables to detect
the creation time of certain data. To get a timestamp, the party
that is interested in proving the creation time of the data, sends
a cryptographic code to the time stamping service provider (TSP).
Finding two data collections with a similar cryptographic code needs
tremendous computing power, unavailable to any modern computer or
computer network. The service provider returns a digitally signed
proof that proves the existence of the said data collection. Since
the time stamping authority sees only a cryptographic code, the
confidentiality of the data is retained.
Private Network (VPN)
Private data network that makes use of the public telecommunication
infrastructure, maintaining privacy through the use of a tunnelling
protocol and security procedures.