Secure Socket Layer

Secure Socket Layer (SSL) provides security to the data that is transferred between web browser and server. SSL encrypts the link between a web server and a browser which ensures that all data passed between them remain private and free from attack. In this article, we are going to discuss SSL in detail, its protocols, the silent features of SSL, and the version of SSL.

What is a Secure Socket Layer ?

SSL, or Secure Sockets Layer, is an Internet security protocol that encrypts data to keep it safe. It was created by Netscape in 1995 to ensure privacy, authentication, and data integrity in online communications. SSL is the older version of what we now call TLS (Transport Layer Security).

Websites using SSL/TLS have “HTTPS” in their URL instead of “HTTP.”

Secure Sockets Layer (SSL) is an encryption security protocol. It provides security to the data that is transferred between web browser and server. SSL encrypts the link between a web server and a browser which ensures that all data passed between them remain private and free from attack.
What is SSL ? (By Rajasthan Computer Teacher Union)

How does SSL work ?

This process is sometimes referred to as an “SSL handshake.” While it sounds like a lengthy process, it takes place in milliseconds. The Handshake process works like this –

A browser or server attempts to connect to a website (i.e., a web server) secured with SSL.
The browser or server requests that the web server identifies itself.
The web server sends the browser or server a copy of its SSL certificate in response.
The browser or server checks to see whether it trusts the SSL certificate. If it does, it signals this to the webserver.
The web server then returns a digitally signed acknowledgment to start an SSL encrypted session.
Encrypted data is shared between the browser or server and the webserver.

Why is SSL Important ?

Originally, data on the web was transmitted in plaintext, making it easy for anyone who intercepted the message to read it. For example, if someone logged into their email account, their username and password would travel across the Internet unprotected.

SSL was created to solve this problem and protect user privacy. By encrypting data between a user and a web server, SSL ensures that anyone who intercepts the data sees only a scrambled mess of characters. This keeps the user’s login credentials safe, visible only to the email service.

Additionally, SSL helps prevent cyber attacks by:

Authenticating Web Servers: Ensuring that users are connecting to the legitimate website, not a fake one set up by attackers.
Preventing Data Tampering: Acting like a tamper-proof seal, SSL ensures that the data sent and received hasn’t been altered during transit.

Secure Socket Layer Protocols

There are some protocols which are used with SSL –

SSL Record Protocol
Handshake Protocol
Change-Cipher Spec Protocol
Alert Protocol

SSL certificate :

Websites need SSL certificates to keep user data secure, verify ownership of the website, prevent attackers from creating a fake version of the site, and convey trust to users.

An SSL certificate is a digital certificate that verifies the authenticity of a website’s identity. It contains the website owner’s public key and is used to initiate secure connections with browsers.
What is SSL Certificate ? (By Rajasthan Computer Teacher Union)

When a website is secured by an SSL certificate, the acronym HTTPS (which stands for Hyper-Text Transfer Protocol Secure) appears in the URL. Without an SSL certificate, only the letters HTTP – i.e., without the S for Secure – will appear. A padlock icon will also display in the URL address bar. This signals trust and provides reassurance to those visiting the website.

To view an SSL certificate’s details, you can click on the padlock symbol located within the browser bar. Details typically included within SSL certificates include:

The domain name that the certificate was issued for
Which person, organization, or device it was issued to
Which Certificate Authority issued it
The Certificate Authority’s digital signature
Associated subdomains
Issue date of the certificate
The expiry date of the certificate
The public key (the private key is not revealed)

Overall, the SSL certificate is an important component of online security, providing encryption, authentication, integrity, non-repudiation, and other key features that ensure the secure and reliable transmission of sensitive information over the internet.

Function of SSL Certificates :

The SSL certificate has several important characteristics that make it a reliable solution for securing online transactions:

Encryption: The SSL certificate uses encryption algorithms to secure the communication between the website or service and its users. This ensures that the sensitive information, such as login credentials and credit card information, is protected from being intercepted and read by unauthorized parties.
Authentication: The SSL certificate verifies the identity of the website or service, ensuring that users are communicating with the intended party and not with an impostor. This provides assurance to users that their information is being transmitted to a trusted entity.
Integrity: The SSL certificate uses message authentication codes (MACs) to detect any tampering with the data during transmission. This ensures that the data being transmitted is not modified in any way, preserving its integrity.
Non-repudiation: SSL certificates provide non-repudiation of data, meaning that the recipient of the data cannot deny having received it. This is important in situations where the authenticity of the information needs to be established, such as in e-commerce transactions.
Public-key cryptography: SSL certificates use public-key cryptography for secure key exchange between the client and server. This allows the client and server to securely exchange encryption keys, ensuring that the encrypted information can only be decrypted by the intended recipient.
Session management: SSL certificates allow for the management of secure sessions, allowing for the resumption of secure sessions after interruption. This helps to reduce the overhead of establishing a new secure connection each time a user accesses a website or service.
Certificates issued by trusted CAs: SSL certificates are issued by trusted CAs, who are responsible for verifying the identity of the website or service before issuing the certificate. This provides a high level of trust and assurance to users that the website or service they are communicating with is authentic and trustworthy.

Types of SSL Certificates :

There are different types of SSL certificates, each suited for different needs:

Single-Domain SSL Certificate: This type covers only one specific domain. A domain is the name of a website, like www.geeksforgeeks.org. For instance, if you have a single-domain SSL certificate for www.geeksforgeeks.org, it won’t cover any other domains or subdomains.
Wildcard SSL Certificate: Similar to a single-domain certificate, but it also covers all subdomains of a single domain. For example, if you have a wildcard certificate for *.geeksforgeeks.org, it would cover www.geeksforgeeks.org, blog.www.geeksforgeeks.org, and any other subdomain under example.com.
Multi-Domain SSL Certificate: This type can secure multiple unrelated domains within a single certificate.

These certificates vary in scope and flexibility, allowing website owners to choose the appropriate level of security coverage based on their needs.