Hypertext Transfer Protocol Secure (HTTPS) is an extension of the Hypertext Transfer Protocol (HTTP). It uses encryption for secure communication over a computer network, and is widely used on the Internet. In HTTPS, the communication protocol is encrypted using Transport Layer Security (TLS) or, formerly, Secure Sockets Layer (SSL). The protocol is therefore also referred to as HTTP over TLS, or HTTP over SSL.
Transport Layer Security (TLS) is a cryptographic protocol designed to provide communications security over a computer network. The protocol is widely used in applications such as email, instant messaging, and voice over IP, but its use in securing HTTPS remains the most publicly visible.
A public key infrastructure (PKI) is a set of roles, policies, hardware, software and procedures needed to create, manage, distribute, use, store and revoke digital certificates and manage public-key encryption.
In cryptography, a public key certificate, also known as a digital certificate or identity certificate, is an electronic document used to prove the validity of a public key. The certificate includes the public key and information about it, information about the identity of its owner, and the digital signature of an entity that has verified the certificate's contents. If the device examining the certificate trusts the issuer and finds the signature to be a valid signature of that issuer, then it can use the included public key to communicate securely with the certificate's subject. In email encryption, code signing, and e-signature systems, a certificate's subject is typically a person or organization. However, in Transport Layer Security (TLS) a certificate's subject is typically a computer or other device, though TLS certificates may identify organizations or individuals in addition to their core role in identifying devices. TLS, sometimes called by its older name Secure Sockets Layer (SSL), is notable for being a part of HTTPS, a protocol for securely browsing the web.
In cryptography, a certificate authority or certification authority (CA) is an entity that stores, signs, and issues digital certificates. A digital certificate certifies the ownership of a public key by the named subject of the certificate. This allows others to rely upon signatures or on assertions made about the private key that corresponds to the certified public key. A CA acts as a trusted third party—trusted both by the subject (owner) of the certificate and by the party relying upon the certificate. The format of these certificates is specified by the X.509 or EMV standard.
CAcert.org is a community-driven certificate authority that issues free X.509 public key certificates. CAcert.org relies heavily on automation and therefore issues only Domain-validated certificates.
The Online Certificate Status Protocol (OCSP) is an Internet protocol used for obtaining the revocation status of an X.509 digital certificate. It is described in RFC 6960 and is on the Internet standards track. It was created as an alternative to certificate revocation lists (CRL), specifically addressing certain problems associated with using CRLs in a public key infrastructure (PKI). Messages communicated via OCSP are encoded in ASN.1 and are usually communicated over HTTP. The "request/response" nature of these messages leads to OCSP servers being termed OCSP responders.
Network Security Services (NSS) is a collection of cryptographic computer libraries designed to support cross-platform development of security-enabled client and server applications with optional support for hardware TLS/SSL acceleration on the server side and hardware smart cards on the client side. NSS provides a complete open-source implementation of cryptographic libraries supporting Transport Layer Security (TLS) / Secure Sockets Layer (SSL) and S/MIME. NSS releases prior to version 3.14 are tri-licensed under the Mozilla Public License 1.1, the GNU General Public License, and the GNU Lesser General Public License. Since release 3.14, NSS releases are licensed under GPL-compatible Mozilla Public License 2.0.
GeoTrust is a digital certificate provider. The GeoTrust brand was bought by Symantec from Verisign in 2010, but agreed to sell the certificate business in August 2017 to private equity and growth capital firm Thoma Bravo LLC. GeoTrust was the first certificate authority to use the domain-validated certificate method which accounts for 70 percent of all SSL certificates on the Internet. By 2006, GeoTrust was the 2nd largest certificate authority in the world with 26.7 percent market share according to independent survey company Netcraft.
The Online Certificate Status Protocol (OCSP) stapling, formally known as the TLS Certificate Status Request extension, is a standard for checking the revocation status of X.509 digital certificates. It allows the presenter of a certificate to bear the resource cost involved in providing Online Certificate Status Protocol (OCSP) responses by appending ("stapling") a time-stamped OCSP response signed by the CA to the initial TLS handshake, eliminating the need for clients to contact the CA, with the aim of improving both security and performance.
Server Name Indication (SNI) is an extension to the Transport Layer Security (TLS) computer networking protocol by which a client indicates which hostname it is attempting to connect to at the start of the handshaking process. The extension allows a server to present one of multiple possible certificates on the same IP address and TCP port number and hence allows multiple secure (HTTPS) websites to be served by the same IP address without requiring all those sites to use the same certificate. It is the conceptual equivalent to HTTP/1.1 name-based virtual hosting, but for HTTPS. This also allows a proxy to forward client traffic to the right server during TLS/SSL handshake. The desired hostname is not encrypted in the original SNI extension, so an eavesdropper can see which site is being requested. The SNI extension was specified in 2003 in RFC 3546
DigiCert, Inc. is a digital security company headquartered in Lehi, Utah. DigiCert provides public key infrastructure (PKI) and validation required for issuing digital certificates or TLS/SSL certificates, acting as a certificate authority (CA) and trusted third party.
The Certification Authority Browser Forum, also known as the CA/Browser Forum, is a voluntary consortium of certification authorities, vendors of Internet browser and secure email software, operating systems, and other PKI-enabled applications that promulgates industry guidelines governing the issuance and management of X.509 v.3 digital certificates that chain to a trust anchor embedded in such applications. Its guidelines cover certificates used for the SSL/TLS protocol and code signing, as well as system and network security of certificate authorities.
StartCom was a certificate authority founded in Eilat, Israel, and later based in Beijing, China, that had three main activities: StartCom Enterprise Linux, StartSSL and MediaHost. StartCom set up branch offices in China, Hong Kong, the United Kingdom and Spain. Due to multiple faults on the company's end, all StartCom certificates were removed from Mozilla Firefox in October 2016 and Google Chrome in March 2017, including certificates previously issued, with similar removals from other browsers expected to follow.
The Transport Layer Security (TLS) protocol provides the ability to secure communications across or inside networks. This comparison of TLS implementations compares several of the most notable libraries. There are several TLS implementations which are free software and open source.
Let's Encrypt is a non-profit certificate authority run by Internet Security Research Group (ISRG) that provides X.509 certificates for Transport Layer Security (TLS) encryption at no charge. It is the world's largest certificate authority, used by more than 300 million websites, with the goal of all websites being secure and using HTTPS. The Internet Security Research Group (ISRG), the provider of the service, is a public benefit organization. Major sponsors include the Electronic Frontier Foundation (EFF), the Mozilla Foundation, OVH, Cisco Systems, Facebook, Google Chrome, Internet Society, AWS, NGINX, and Bill and Melinda Gates Foundation. Other partners include the certificate authority IdenTrust, the University of Michigan (U-M), and the Linux Foundation.
The Automatic Certificate Management Environment (ACME) protocol is a communications protocol for automating interactions between certificate authorities and their users' servers, allowing the automated deployment of public key infrastructure at very low cost. It was designed by the Internet Security Research Group (ISRG) for their Let's Encrypt service.
J. Alex Halderman is professor of computer science and engineering at the University of Michigan, where he is also director of the Center for Computer Security & Society. Halderman's research focuses on computer security and privacy, with an emphasis on problems that broadly impact society and public policy.
Peter Daniel Eckersley was an Australian computer scientist, computer security researcher and activist. From 2006 to 2018, he worked at the Electronic Frontier Foundation, including as chief computer scientist and head of AI policy. In 2018, he left the EFF to become director of research at the Partnership on AI, a position he held until 2020. In 2021, he co-founded the AI Objectives Institute.
Rustls is an open-source implementation of the Transport Layer Security (TLS) cryptographic protocol written in the Rust programming language. TLS is essential to internet security, and Rustls aims to enable secure, fast TLS connections. Rustls uses Rust's enforcement of memory safety to reduce the risk of security vulnerabilities. It is part of efforts to improve internet security by replacing memory-unsafe software libraries, such as OpenSSL, with memory-safe alternatives.
