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<chapter>
  <header>
    <copyright>
      <year>2015</year>
      <year>2018</year>
      <holder>Ericsson AB, All Rights Reserved</holder>
    </copyright>
    <legalnotice>
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
 
      http://www.apache.org/licenses/LICENSE-2.0

  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.

  The Initial Developer of the Original Code is Ericsson AB.
    </legalnotice>

    <title>Introduction</title>
    <prepared>OTP team</prepared>
    <docno></docno>
    <date>2015-03-05</date>
    <rev>A</rev>
    <file>ssl_introduction.xml</file>
  </header>

  <section>
    <title>Purpose</title>
    <p>Transport Layer Security (TLS) and its predecessor, the Secure
    Sockets Layer (SSL), are cryptographic protocols designed to
    provide communications security over a computer network. The protocols
    use X.509 certificates and hence public key (asymmetric) cryptography to
    authenticate the counterpart with whom they communicate,
    and to exchange a symmetric key for payload encryption. The protocol provides
    data/message confidentiality (encryption), integrity (through message authentication code checks)
    and host verification (through certificate path validation). DTLS (Datagram Transport Layer Security) that
    is based on TLS but datagram oriented instead of stream oriented.</p>
  </section>

  <section>
    <title>Prerequisites</title>
    <p>It is assumed that the reader is familiar with the Erlang
    programming language, the concepts of OTP, and has a basic
    understanding of SSL/TLS/DTLS.</p>
  </section>

</chapter>
