What is HTTPS?
HTTPS (Hypertext Transfer Protocol over Secure Socket Layer, or HTTP over SSL) is a web protocol developed by Netscape.
One can say: HTTPS = HTTP + SSL
HTTPS uses Secure Socket Layer (SSL) as a sublayer under its regular HTTP application layering.
Need of HTTPS:
Hypertext
Transfer Protocol (HTTP) is a protocol for transmitting and receiving
information across the Internet. HTTP serves as a request and response
procedure that all agents on the Internet follow so that information can
be rapidly, easily, and accurately disseminated between servers, which
hold information, and clients, who are trying to access it. You normally
use HTTP when you are browsing the web, its not secure, so someone can
eavesdrop on the conversation between your computer and the web server.
In many cases, clients may be exchanging confidential information with a
server, which needs to be secured in order to prevent unauthorized
access. For this reason, https, or secure http, was developed by
Netscape corporation to allow authorization and secured transactions.
Similarity between HTTP and HTTPS:
In many ways,
https is identical to http, because it follows the same basic protocols.
The http or https client, such as a Web browser, establishes a
connection to a server on a standard port. When a server receives a
request, it returns a status and a message, which may contain the
requested information or indicate an error if part of the process
malfunctioned. Both systems use the same Uniform Resource Identifier
(URI) scheme, so that resources can be universally identified. Use of
https in a URI scheme rather than http indicates that an encrypted
connection is desired.
Difference between HTTP and HTTPS:
1. URL begins with “http://" in case of HTTP while the URL begins with “https://” in case of HTTPS.
2. HTTP is unsecured while HTTPS is secured.
3. HTTP uses port 80 for communication while HTTPS uses port 443 for communication.
4. HTTP operates at Application Layer while HTTPS operates at Transport Layer.
5. No encryption is there in HTTP while HTTPS uses encryption.
6. No certificates required in HTTP while certificates required in HTTPS.
How HTTPS works?
For HTTPS connection, public key and signed certificates are required for the server.
When using an
https connection, the server responds to the initial connection by
offering a list of encryption methods it supports. In response, the
client selects a connection method, and the client and server exchange
certificates to authenticate their identities. After this is done, both
parties exchange the encrypted information after ensuring that both are
using the same key, and the connection is closed. In order to host https
connections, a server must have a public key certificate, which embeds
key information with a verification of the key owner's identity. Most
certificates are verified by a third party so that clients are assured
that the key is secure.
In other words, we can say, HTTPS works similar to HTTP but SSL adds some spice in it.
HTTP includes the following actions:
1. The browser opens a TCP connection.
2. The browser sends a HTTP request to the server
3. The server sends a HTTP response to the browser. 4. The TCP connection is closed.
SSL will include the following actions:
1. Authenticate the server to the client.
2. Allow the client and server to select the cryptographic algorithms, or ciphers, that they both support.
3. Optionally authenticate the client to the server.
4. Use public-key encryption techniques to generate shared secrets.
5. Establish an encrypted SSL connection.
6. Once the SSL connection is established the usual transfer of HTTP requests will continue.
Where should https be used?
HTTPS should be
used in Banking Websites, Payment Gateway, Shopping Websites, Login
Pages, Emails (Gmail offers HTTPS by default in Chrome browser) and
Corporate Sector Websites. For example:
