DigiCert Inc is a privately held, US based X.509

X.509

In cryptography, X.509 is an ITU-T standard for a public key infrastructure and Privilege Management Infrastructure . X.509 specifies, amongst other things, standard formats for public key certificates, certificate revocation lists, attribute certificates, and a certification path validation...

 SSL

Transport Layer Security

Transport Layer Security and its predecessor, Secure Sockets Layer , are cryptographic protocols that provide communication security over the Internet...

 certificate provider. As a trusted third party

Trusted third party

In cryptography, a trusted third party is an entity which facilitates interactions between two parties who both trust the third party; The Third Party reviews all critical transaction communications between the parties, based on the ease of creating fraudulent digital content. In TTP models, the...

, DigiCert verifies the authenticity of secure websites on behalf of a web browser for the purpose of preventing online phishing

Phishing

Phishing is a way of attempting to acquire information such as usernames, passwords, and credit card details by masquerading as a trustworthy entity in an electronic communication. Communications purporting to be from popular social web sites, auction sites, online payment processors or IT...

 scams.

DigiCert was established in 2003 by Ken Bretschneider, CEO

Chief executive officer

A chief executive officer , managing director , Executive Director for non-profit organizations, or chief executive is the highest-ranking corporate officer or administrator in charge of total management of an organization...

, and is currently the 5th largest public certificate authority

Certificate authority

In cryptography, a certificate authority, or certification authority, is an entity that issues digital certificates. The digital certificate certifies the ownership of a public key by the named subject of the certificate...

 in the world with customers such as Facebook

Facebook

Facebook is a social networking service and website launched in February 2004, operated and privately owned by Facebook, Inc. , Facebook has more than 800 million active users. Users must register before using the site, after which they may create a personal profile, add other users as...

 and AOL

AOL

AOL Inc. is an American global Internet services and media company. AOL is headquartered at 770 Broadway in New York. Founded in 1983 as Control Video Corporation, it has franchised its services to companies in several nations around the world or set up international versions of its services...

.

As a founding member of the CA/Browser Forum

CA/Browser Forum

The Certification Authority Browser Forum, also known as CA/Browser Forum, is a voluntary consortium of certification authorities and browser industry leaders that created the SSL certificates, and vendors of Internet browser software and other applications....

, DigiCert assisted in the development of the Extended Validation Certificate. DigiCert also worked in conjunction with Microsoft to develop and promote the use of subject alternate names in SSL certificates, for use with Microsoft Exchange Server

Microsoft Exchange Server

Microsoft Exchange Server is the server side of a client–server, collaborative application product developed by Microsoft. It is part of the Microsoft Servers line of server products and is used by enterprises using Microsoft infrastructure products...

.

DigiCert is the largest public CA that does not issue "domain validated," "low assurance," or "instant" SSL certificates either directly or through a subsidiary brand.

DigiCert Inc. is of no relation to Digicert Sdn. Bhd, a Malaysian-based certification authority.