What is SSL? Definition and More


Secure Sockets Layer (SSL) was the most widely used cryptographic technique for providing security over internet connections before TLS (Transport Layer Security) was released in 1999. Despite the fact that the SSL protocol has been deprecated and TLS has been adopted in its stead, most people still refer to this type of technology as “SSL.”

What is SSL?

SSL establishes a secure link between two computers or devices connected to the internet or a private network. This is a common example of Secure Sockets Layer being used to protect communication between a web browser and a web server. This changes the address of a website from HTTP to HTTPS, with the ‘S’ indicating ‘secure.’

Because the data being transported from the web browser to the web server or between other endpoints is transmitted in plaintext, HTTP is not secure and vulnerable to eavesdropping attacks.

As a result, attackers have the ability to intercept and see sensitive information such as credit card numbers and account logins. Secure Sockets Layer ensures that anything transmitted or posted through a browser utilizing HTTPS is encrypted and protected from interception.

How Can We Know if a Website is SSL Secure?

When it comes to setting up a secure session, SSL is a transparent technology that requires little interaction from the end-user. When using a browser, you can identify if a site is using Secure Sockets Layer by looking for a padlock or seeing HTTPS instead of HTTP in the address bar.

Why Do I Need a Secure Socket Layer?

The internet has exploded with millions of transactions and communications happening every day. Unfortunately, this also means more opportunities for hackers and other ill-intent activities.

Hence, it is now more than ever important to secure your connection to the web using the Secure Sockets Layer. The following information security principles are supported by SSL:

  1. Encryption – It is a method of securing data communications. (For example, browser to the server, server to server, application to server, and so on.)
  2. Authentication – It is a check to ensure that the server you’re connected to is the right one.
  3. Data Integrity – Ensure data integrity by ensuring that the data requested or submitted is delivered.

Secure Sockets Layer can be used to protect the following:

  • Transactions involving credit cards or other forms of online payment.
  • Intranet-based traffic, i.e., internal networks, file sharing, extranets, and database connectivity.
  • Outlook Web Access, Exchange, and Office Communications Server are examples of webmail servers.
  • The connection between a client email program like Microsoft Outlook and a server email program like Microsoft Exchange.
  • Website owners upgrading new pages on their websites or uploading large files use HTTPS and FTP services to transfer files.
  • Logins to applications and control panels such as Parallels and cPanel.
  • Citrix Delivery Platforms or cloud-based computing platforms are examples of workflow and virtualization solutions.

What is the Best Port to Use for SSL?

Port 443 is the standard, and so recommended, port for encrypted SSL connections for optimum compatibility. Any port, however, can be utilized.

What is the Distinction Between a Digital Certificate and an SSL Certificate?

An SSL certificate, also called TLS or SSL/TLS certificate, is a digital document that identifies a website using a cryptographic key pair consisting of a public and private key.

The public key allows a web browser to establish an encrypted communication session with a web server using TLS and HTTPS. The server stores the private key, which is used to digitally sign web pages and other data (such as images and JavaScript files).

An SSL certificate also contains identifying information about a website, such as its domain name and, optionally, identifying information about the site’s owner.

If the web server’s SSL certificate is certified by a publicly trusted certificate authority (CA), such as SSL.com, end users’ web browsers and operating systems will trust digitally signed content from the server as authentic. An SSL certificate is a type of X.509 certificate.

What is TLS?

TLS or Transport Layer Security is the successor to the Secure Sockets Layer protocol for authentication and encryption, which was released in 1999. RFC 8446 is where TLS 1.3 is defined (August 2018).

SSL/TLS works by using digital documents called X.509 certificates to link the identities of entities like websites and businesses to cryptographic key pairs. A private key and a public key make up each key pair; the private key is kept confidential, but the public key can be shared extensively using a certificate. The private and public keys, along with a publicly trusted certificate, can be used to negotiate an encrypted and authenticated communication session over the internet.

The person or organization who requests the certificate generates a pair of public and private keys, which should be kept on the server under protection. A publicly trusted CA verifies the information in the CSR and generates a signed certificate that the requester can install on his or her web server. The level of confidence conferred by SSL/TLS certificates is determined by the validation methods employed and the level of trust conferred.

What is the Current Version of TLS?

TLS 1.3 is the most recent version of SSL/TLS, as described by RFC 8446 in August 2018. TLS 1.2 (RFC 5246) was established in August 2008 and is still widely used. SSL/TLS versions previous to TLS 1.2 are deemed insecure and should be avoided.

What Difficulties do Older Versions of TLS Have in Terms of Security?

In the previous two decades, security researchers have discovered a large number of protocol and implementation issues in TLS versions 1.0 and 1.1.

Attacks like ROBOT influenced the RSA key exchange algorithm, while LogJam and WeakDH showed that many TLS servers might be duped into providing incorrect parameters for alternative key exchange schemes. By compromising a key exchange, attackers can completely breach network security and decrypt communications.

Various RC4 or CBC-mode ciphers, which were supported in TLS 1.2 and earlier, have been shown to be vulnerable to attacks on symmetric ciphers like BEAST or Lucky13. Even signatures were subject to Bleichenbacher’s RSA signature forgery attack and other related padding attacks.

TLS 1.2 is still vulnerable to downgrade attacks such as POODLE, FREAK, and CurveSwap, however, the bulk of these attacks have been mitigated in TLS 1.3. (Assuming that TLS instances are configured correctly). This is the situation since all versions of the TLS protocol prior to 1.3 do not protect the handshake negotiation (which decides the protocol version that will be used throughout the exchange).


Secure Sockets Layer is an encryption technique for making the connections over the internet secure. Although its successor TLS is growing in terms of adoption, many organizations still rely on SSL, and hence, it is important to know about it when it comes to network security and securing yourself over the internet.

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