SSL (Secure Sockets Layer) and its successor TLS (Transport Layer Security) are cryptographic protocols that secure internet connections between clients and servers. SSL was originally developed by Netscape in the 1990s to provide HTTPS secure connections for web browsing. It uses public/private key encryption and digital certificates to authenticate servers and establish encrypted connections to securely transmit data over TCP/IP networks like the internet. TLS improved upon SSL by addressing security vulnerabilities and supporting newer encryption algorithms. HTTP (Hypertext Transfer Protocol) is the underlying protocol used to request and transmit web pages and other files over the internet. Combining HTTP with SSL/TLS results in HTTPS, the secure version of HTTP used for encrypted web browsing and transactions.

2. Presentation plan
 What is HTTP?

3. Presentation plan
 What is SSL?

4. What is SSL?
 Secure Sockets Layer (SSL) is a computer networking protocol for securing
connections between network application clients and servers over an insecure
network, such as the internet, due to numerous protocol and implementation
flaws and vulnerabilities
 SSL was originally specified in the 1990s as a proprietary protocol that
allowed Netscape browser clients using the Hypertext Transfer Protocol
(HTTP) to communicate securely with Netscape web servers. SSL eventually
came to be used to secure authentication and encryption for communication
at the network transport layer.
Netscape Communications was a computer services company best known for its Web browser, Navigator.
Navigator was one of the two most popular Web browsers in the 1990s.

5. Presentation plan
 What is SSL?
 How does SSL work?

6. How does SSL work?
 SSL runs above the transport layer and the network layer, which are
responsible for the transport of data between processes and the routing of
network traffic over a network between client and server, respectively, and
below application layer protocols such as HTTP and the SMTP (Simple Mail
Transport Protocol).
 The "sockets" part of the term refers to the sockets method of passing data
between a client and a server program in a network, or between processes in
the same computer.

7. How does SSL work?
SSL uses a combination
of public key and
symmetric key encryption
to secure a connection
between two machines,
typically a web or mail
server and a client system,
communicating over
the internet or
another TCP/IP network.

8. How does SSL work?
The SSL protocol includes two subprotocols:
the record protocol
the "handshake" protocol.

9. The record protocol
• The record protocol defines how communicating hosts exchange data using
SSL, including specifications for how data is to be prepared for transmission
and how it is to be verified or decrypted on receipt.

10. The handshake protocol
•The handshake protocol defines how a client and server establish an SSL
connection, including the negotiation of which cryptographic systems each host
is willing (or unwilling) to use for communication, as well as the exchange of
cryptographic material, such as public keys and session keys for encryption or
authentication of transmitted data.

11. How does SSL work?
 Once the server has been authenticated, the client and server
establish cipher settings and a shared key to encrypt the information they
exchange during the remainder of the session. This provides data
confidentiality and integrity.

12. How does SSL work?
 This whole process is invisible to the user. For example, if a webpage requires
an SSL connection, the URL will change from HTTP to HTTPS, and a padlock
icon will appear in the browser once the server has been authenticated.

13. How does SSL work?
•The handshake also allows the client to authenticate itself to the server. In this
case, after server authentication is complete, the client must present its
certificate to the server to authenticate the client's identity before the
encrypted SSL session can be established.

14. Presentation plan
 What is HTTP?
 What is SSL?
 How does SSL work?
 What is TSL?

15. What is TSL?
 After the IETF officially took over the SSL protocol to standardize it through
an open process, version 3.1 of SSL was released as TLS 1.0.

16. What is SSL?
 SSL was deprecated for use on the internet by the Internet Engineering Task Force
(IETF) in 2015 and has been replaced by the Transport Layer Security (TLS) protocol.
While TLS and SSL are not interoperable, TLS is backwards-compatible with SSL 3.0.

17. What is TSL?
 Many attacks against SSL have focused on SSL implementation issues, but
the POODLE (Padding Oracle On Downgraded Legacy Encryption) vulnerability
is a known flaw in the SSL 3.0 protocol itself, exploiting the way in which it
ignores padding bytes when running in cipher block chaining mode.
 This flaw allows an attacker to decrypt sensitive information, such as
authentication cookies. TLS 1.0 is not vulnerable to this attack because it
specifies that all padding bytes must have the same value and must be
verified.

18. What is TSL?
 Other key differences between SSL and TLS that make TLS a more secure and
efficient protocol are:
 message authentication,
 key material generation,
 cipher suites, TLS supporting newer and more secure algorithms.
 TLS 1.2 is the most recent version, but publication of the next version is
expected to be approved in 2017; the update is likely to be called either TLS
1.3 or TLS 2.0.

19. Presentation plan
 What is SSL?
 How does SSL work?
 What is TSL?
 What is HTTP?

20. What is HTTP?
 HTTP (Hypertext Transfer Protocol) is the set of rules for transferring files
(text, graphic images, sound, video, and other multimedia files) on the World
Wide Web. As soon as a Web user opens their Web browser, the user is
indirectly making use of HTTP. HTTP is an application protocol that runs on
top of the TCP/IP suite of protocols (the foundation protocols for the
Internet).
 HTTP concepts include the idea that files can contain references to other
files whose selection will elicit additional transfer requests. Any Web
server machine contains, in addition to the Web page files it can serve, an
HTTP daemon, a program that is designed to wait for HTTP requests and
handle them when they arrive.

21. What is HTTP?
 The Web browser is an HTTP client, sending requests to server machines.
When the browser user enters file requests by either "opening" a Web file
(typing in a Uniform Resource Locator or URL) or clicking on a hypertext link,
the browser builds an HTTP request and sends it to the Internet Protocol
address (IP address) indicated by the URL.
 The HTTP daemon in the destination server machine receives the request and
sends back the requested file or files associated with the request. (A Web
page often consists of more than one file.)

22. What is HTTPS?
HTTP + SSL/TSL = HTTPS (Hypertext Transfer Protocol Secure)

23. Thank you for your attention