View source for Transport Layer Security (nonfiction)

'''Transport Layer Security''' ('''TLS'''), and its now-deprecated predecessor, '''Secure Sockets Layer''' ('''SSL'''), are cryptographic protocols designed to provide communications security over a computer network. Several versions of the protocols find widespread use in applications such as web browsing, email, instant messaging, and voice over IP (VoIP). Websites can use TLS to secure all communications between their servers and web browsers.

== Description ==

The TLS protocol aims primarily to provide privacy and data integrity between two or more communicating computer applications. When secured by TLS, connections between a client (e.g., a web browser) and a server (e.g., wikipedia.org) should have one or more of the following properties:

* The connection is private (or secure) because symmetric cryptography is used to encrypt the data transmitted. The keys for this symmetric encryption are generated uniquely for each connection and are based on a shared secret that was negotiated at the start of the session (TLS handshake). The server and client negotiate the details of which encryption algorithm and cryptographic keys to use before the first byte of data is transmitted. The negotiation of a shared secret is both secure (the negotiated secret is unavailable to eavesdroppers and cannot be obtained, even by an attacker who places themselves in the middle of the connection) and reliable (no attacker can modify the communications during the negotiation without being detected).
* The identity of the communicating parties can be authenticated using public-key cryptography. This authentication can be made optional, but is generally required for at least one of the parties (typically the server).
* The connection is reliable because each message transmitted includes a message integrity check using a message authentication code to prevent undetected loss or alteration of the data during transmission.

In addition to the properties above, careful configuration of TLS can provide additional privacy-related properties such as forward secrecy, ensuring that any future disclosure of encryption keys cannot be used to decrypt any TLS communications recorded in the past.

TLS supports many different methods for exchanging keys, encrypting data, and authenticating message integrity. As a result, secure configuration of TLS involves many configurable parameters.

Attempts have been made to subvert aspects of the communications security that TLS seeks to provide, and the protocol has been revised several times to address these security threats.

Developers of web browsers have also revised their products to defend against potential security weaknesses after these were discovered (see TLS/SSL support history of web browsers).

The TLS protocol comprises two layers: 

* The TLS record
* The TLS handshake protocols

TLS is a proposed Internet Engineering Task Force (IETF) standard, first defined in 1999, and the current version is TLS 1.3 defined in RFC 8446 (August 2018). TLS builds on the earlier SSL specifications (1994, 1995, 1996) developed by Netscape Communications for adding the HTTPS protocol to their Navigator web browser.

== Digital certificates ==

Main article: [[Public key certificate (nonfiction)|Public key certificate]]

A [[Public key certificate (nonfiction)|digital certificate]] certifies the ownership of a public key by the named subject of the certificate, and indicates certain expected usages of that key. This allows others (relying parties) to rely upon signatures or on assertions made by the private key that corresponds to the certified public key.

== Certificate authorities ==

Main article: [[Certificate authority (nonfiction)|Certificate authority]]

TLS typically relies on a set of trusted third-party certificate authorities to establish the authenticity of certificates. Trust is usually anchored in a list of certificates distributed with user agent software, and can be modified by the relying party.

According to Netcraft, who monitors active TLS certificates, the market-leading certificate authority (CA) has been Symantec since the beginning of their survey (or VeriSign before the authentication services business unit was purchased by Symantec). Symantec currently accounts for just under a third of all certificates and 44% of the valid certificates used by the 1 million busiest websites, as counted by Netcraft.

As a consequence of choosing X.509 certificates, certificate authorities and a public key infrastructure are necessary to verify the relation between a certificate and its owner, as well as to generate, sign, and administer the validity of certificates. While this can be more convenient than verifying the identities via a web of trust, the 2013 mass surveillance disclosures made it more widely known that certificate authorities are a weak point from a security standpoint, allowing man-in-the-middle attacks (MITM) if the certificate authority cooperates (or is compromised).

== Notes ==

A SSL/TLS Manager allows the generation of:

* SSL certificates
* Certificate signing requests
* Private keys

These are all parts of using SSL to secure a website. 

SSL allows you to secure pages on your site so that information such as logins, credit card numbers, etc are sent encrypted instead of plain text. 

It is important to secure your site’s login areas, shopping areas, and other pages where sensitive information could be sent over the web.

== In the News ==

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== Fiction cross-reference ==

* [[Evil bit release]]
* [[Gnomon algorithm]]
* [[Gnomon Chronicles]]

== Nonfiction cross-reference ==

* [[Certificate authority (nonfiction)]] - a certificate authority or certification authority (CA) is an entity that issues digital certificates. A digital certificate certifies the ownership of a public key by the named subject of the certificate. This allows others (relying parties) 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. One particularly common use for certificate authorities is to sign certificates used in HTTPS, the secure browsing protocol for the World Wide Web. Another common use is in issuing identity cards by national governments for use in electronically signing documents.
* [[Evil bit (nonfiction)]]
* [[Public key certificate (nonfiction)]] - a public key certificate, also known as a digital certificate or identity certificate, is an electronic document used to prove the ownership of a public key.[1] The certificate includes information about the key, information about the identity of its owner (called the subject), and the digital signature of an entity that has verified the certificate's contents (called the issuer). If the signature is valid, and the software examining the certificate trusts the issuer, then it can use that key to communicate securely with the certificate's subject.

== External links ==

* [https://en.wikipedia.org/wiki/Transport_Layer_Security Transport Security Layer] @ Wikipedia


[[Category:Nonfiction (nonfiction)]]
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[[Category:Internet (nonfiction)]]