SSL (Secure Sockets Layer)

Last updated: February 8, 2026Reviewed date: February 8, 2026Reading time: 13 min read

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SSL (Secure Sockets Layer) and its successor, TLS (Transport Layer Security), are protocols for establishing authenticated and encrypted links between networked computers. Although the SSL protocol was deprecated with the release of TLS 1.0 in 1999, it is still common to refer to these related technologies as...

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Article Summary

Key Takeaways

This article explains What is SSL? in simple medical language.
This article explains What is TLS? in simple medical language.
This article explains Main Differences between the SSL and TLS in simple medical language.
This article explains Head to Head Comparison of SSL and TLS in simple medical language.

Educational health guideWritten for patient understanding and clinical awareness.

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Emergency safety firstUrgent warning signs are highlighted below.

Seek urgent medical care if you notice

These warning signs are general safety guidance. Local emergency numbers and clinical judgment should always come first.

Severe symptoms, breathing difficulty, fainting, confusion, or rapidly worsening illness.
New weakness, severe pain, high fever, or symptoms after a serious injury.
Any symptom that feels urgent, unusual, or unsafe for the patient.

Emergency now

Use emergency care for severe, sudden, rapidly worsening, or life-threatening symptoms.

See a doctor

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SSL (Secure Sockets Layer) and its successor, TLS (Transport Layer Security), are protocols for establishing authenticated and encrypted links between networked computers. Although the SSL protocol was deprecated with the release of TLS 1.0 in 1999, it is still common to refer to these related technologies as “SSL” or “SSL/TLS.”

An SSL certificate (also known as a TLS or SSL/TLS certificate) is a digital document that binds the identity of a website to a cryptographic key pair consisting of a public key and a private key. The public key, included in the certificate, allows a web browser to initiate an encrypted communication session with a web server via the TLS and HTTPS protocols. The private key is kept secure on the server, and is used to digitally sign web pages and other documents (such as images and JavaScript files).

An SSL certificate also includes identifying information about a website, including its domain name and, optionally, identifying information about the site’s owner. If the web server’s SSL certificate is signed by a publicly trusted certificate authority (CA), like SSL.com, digitally signed content from the server will be trusted by end users’ web browsers and operating systems as authentic.

Both SSL and TLS are cryptographic protocols between networked servers, computers, and devices for authentication and data encryption. SSL is 25 years old. Netscape developed the first version of SSL (version 1.0) in 1995, but it was not released because of its critical security vulnerabilities. SSL 2.0 was not good, and SSL 3.0 was published just over a year later. Unanimous development, people participated in it and developed TLS 1.0. TLS 1.0 is very similar to SSL 3.0, but there is enough difference to reduce it to SSL 3.0 in advance.

In this topic, we will discuss the difference between SSL and TLS. But firstly, we need to know the SSL and TLS.

What is SSL?

Secure Socket Layer (SSL) is the most used internet security cryptographic protocol before Transport Layer Security (TLS) was released in 1990. However, the SSL protocol has been discontinued, but the TLS has now adopted it. Most people call it SSL. SSL provides a secure link between two devices or computers linked to the internet or the internal network.

What is TLS?

TLS is a popular security protocol designed for Internet communication to enhance privacy and data security. It is generally used to encrypt communication among web packages and servers, including a web browser loading page. It can be used for encrypting different voice messages for texts and IPs. It was introduced by the Internet Technology Task Force (IETF) of the International Standards Organization (ISO), which launched the primary protocol in 1999. In 2018, the latest version was released and contained TLS 1.3.

Main Differences between the SSL and TLS

Here, we are going to discuss the main differences between SSL and TLS.

The SSL is a secure socket layer, whereas the TSL is a Transportation Layer Protection.
The SSL and TLS cryptographic protocols authenticate server-to-device data transfers. For example, a cryptographic protocol encrypts data exchanged between the Web server and a user.
A secure framework is needed to encrypt the data from both sides. An SSL/TLS certificate supports this. It serves as an encryption portal for encrypting information that prevents unauthorized entry by hackers.
For SSL message authentication, key information and configuration data are needed on an ad hoc basis, even as the TLS model depends on the authentication code for the HMAC hash.
SSL was a first-kind cryptographic protocol. On the other hand, TLS was the latest modified SSL version.

Head to Head Comparison of SSL and TLS

Here, we are going to discuss head to head comparison of SSL and TLS in tabular form:

SSL	TOOLS
For Fortezza, SSL supports the Cipher Suite.	The encryption of Fortezza doesn’t support TLS.
It makes use of the Message Authentication (MAC) code for the record protocol.	It makes use of Hashed MAC for the Record Protocol.
The SSL uses the pre-master secret message digest for the generation of master secrets.	It is a slightly different way of defining master confidentiality in the TLS.
Verify the complex in the SSL Certificate.	In the TLS, Sample Certificate Verification.
Included in the SSL alert message is “no certificate”.	It removes the summary of the alarm and adds a dozen other values.
SSL message authentication offers ad-hoc key information and client data.	The TLS version is based on the HMAC Hash Message’s authentication code.

Keys, Certificates, and Handshakes

SSL/TLS works by binding the identities of entities such as websites and companies to cryptographic key pairs via digital documents known as X.509 certificates. Each key pair consists of a private key and a public key. The private key is kept secure, and the public key can be widely distributed via a certificate.

The special mathematical relationship between the private and public keys in a pair means that it is possible to use the public key to encrypt a message that can only be decrypted with the private key. Furthermore, the holder of the private key can use it to sign other digital documents (such as web pages), and anyone with the public key can verify this signature.

For a detailed comparison of the two most widely used digital signature algorithms used in SSL/TLS, please read our article, Comparing ECDSA vs RSA.

If the SSL/TLS certificate itself is signed by a publicly trusted certificate authority (CA), such as SSL.com, the certificate will be implicitly trusted by client software such as web browsers and operating systems. Publicly trusted CAs have been approved by major software suppliers to validate identities that will be trusted on their platforms. A public CA’s validation and certificate issuance procedures are subject to regular, rigorous audits to maintain this trusted status.

Via the SSL/TLS handshake, the private and public keys can be used with a publicly trusted certificate to negotiate an encrypted and authenticated communication session over the internet, even between two parties who have never met. This simple fact is the foundation of secure web browsing and electronic commerce as it is known today.

Not all applications of SSL/TLS require public trust. For example, a company can issue its own privately trusted certificates for internal use. For more information, please read our article on Private vs. Public PKI.

SSL/TLS and Secure Web Browsing

The most common and well-known use of SSL/TLS is secure web browsing via the HTTPS protocol. A properly configured public HTTPS website includes an SSL/TLS certificate that is signed by a publicly trusted CA. Users visiting an HTTPS website can be assured of:

Authenticity. The server presenting the certificate has a private key that matches the public key in the certificate.
Integrity. Documents signed by the certificate (e.g. web pages) have not been altered in transit by a man in the middle.
Encryption. Communications between the client and server are encrypted.

Because of these properties, SSL/TLS and HTTPS allow users to securely transmit confidential information such as credit card numbers, social security numbers, and login credentials over the internet and be sure that the website they are sending them to is authentic. With an insecure HTTP website, these data are sent as plain text, readily available to any eavesdropper with access to the data stream. Furthermore, users of these unprotected websites have no trusted third-party assurance that the website they are visiting is what it claims to be.

Look for the following indicators in your browser’s address bar to be sure that a website you are visiting is protected with a trusted SSL/TLS certificate (screenshot from Firefox 70.0 on macOS) :

A closed padlock icon to the left of the URL. Depending on your browser and the type of certificate the website has installed, the padlock maybe green and/or accompanied by identifying information about the company running it.
If shown, the protocol at the beginning of the URL should be
HTTPS://
, not
HTTP://
. Note that not all browsers display the protocol.

Modern desktop browsers also alert visitors to insecure websites that do not have an SSL/TLS certificate. The screenshot below is of an insecure website viewed in Firefox and shows a crossed-out padlock to the left of the URL

Obtaining an SSL/TLS Certificate

Ready to secure your website? The basic procedure for requesting a publicly trusted SSL/TLS website certificate is as follows:

The person or organization requesting the certificate generates a pair of public and private keys, preferably on the server to be protected.
The public key, along with the domain name(s) to be protected and (for OV and EV certificates) organizational information about the company requesting the certificate, is used to generate a certificate signing request (CSR).
- Please see this FAQ for instructions on generating a key pair and CSR on many server platforms.
The CSR is sent to a publicly trusted CA (such as SSL.com). The CA validates the information in the CSR and generates a signed certificate that can be installed on the requester’s web server.
- For instructions on ordering SSL/TLS certificates from SSL.com, please see this how-to.

SSL/TLS certificates vary depending on the validation methods used and the level of trust they confer, with extended validation (EV) offering the highest level of trust. For information on the differences between the major validation methods (DV, OV, and EV), please refer to our article, DV, OV, and EV certificates.

FAQ

What does SSL mean?

Secure Sockets Layer. SSL stands for Secure Sockets Layer.

What is the difference between SSL and HTTPS?

HTTPS: HTTPS is a combination of HTTP with SSL/TLS. It means that HTTPS is an HTTP connection which is delivering the data secured using SSL/TLS. SSL: SSL is a secure protocol that works on top of HTTP to provide security.

What are SSL and TLS?

SSL (Secure Socket Layer) and TLS (Transport Layer Security) are popular cryptographic protocols that are used to imbue web communications with integrity, security, and resilience against unauthorized tampering.

Does SSL mean HTTPS?

HTTPS is a combination of the Hypertext Transfer Protocol (HTTP) with either SSL or TLS. It provides encrypted communications and a secure ID of a web server. SSL is simply a protocol that enables secure communications online.

Why do we need SSL?

Companies and organizations need to add SSL certificates to their websites to secure online transactions and keep customer information private and secure. In short: SSL keeps internet connections secure and prevents criminals from reading or modifying information transferred between two systems.

Is SSL secure?

Many people believe that an SSL Certificate means a website is safe to use. Just because a website has a certificate, or starts with HTTPS, does not guarantee that it is 100% secure and free from malicious code. It just means that the website is probably safe. In the vast majority of cases, the sites will be.

What is TCP vs SSL?

SSL/TLS protocol makes TCP a secure protocol, and whenever an application needs to send sensitive information over the internet, it is a requirement to use the send over SSL. oftentimes the SSL protocol is used to secure — the application network layer — HTTP protocol.

Can you use SSL with HTTP?

HTTPS is HTTP with encryption. The only difference between the two protocols is that HTTPS uses TLS (SSL) to encrypt normal HTTP requests and responses. As a result, HTTPS is far more secure than HTTP. A website that uses HTTP has HTTP:// in its URL, while a website that uses HTTPS has HTTPS://.

Which is better TLS or SSL?

To sum everything up, TLS and SSL are both protocols to authenticate and encrypt the transfer of data on the Internet. The two are tightly linked and TLS is just the more modern, secure version of SSL.

Is Gmail SSL or TLS?

By default, Gmail always tries to use TLS when sending emails. However, a secure TLS connection requires that both the sender and recipient use TLS. If the receiving server doesn’t use TLS, Gmail still delivers messages, but the connection isn’t secure.

Can TLS be hacked?

Good news: researchers say it’s “very hard to exploit” and major vendors have already released security patches for it. A team of researchers has documented a vulnerability in TLS 1.2 (and earlier versions) that could allow a man-in-the-middle attacker to acquire a shared session key and decrypt SSL/TLS traffic.

How does SSL VPN Work?

SSL VPNs rely on the TLS protocol, which has replaced the older SSL protocol, to secure remote access. SSL VPNs enable authenticated users to establish secure connections to internal HTTP and HTTPS services via standard web browsers or client applications that enable direct access to networks.

What is SSL iPhone?

The Secure Sockets Layer (SSL) provides encryption for TCP/IP connections as they transit the Internet and local networks between a client and a server. In the case of iPhone email, SSL encrypts all of the communication between your phone and your mail server.

Is SSL necessary for the website?

SSL / HTTPS is recommended for all websites on the internet. However, it is required for all websites that collect user information like login details, payment information, credit cards, and more.

What is an example of SSL?

One common example is when SSL is used to secure communication between a web browser and a web server. This turns a website’s address from HTTP to HTTPS, the ‘S’ standing for ‘secure’.

How does SSL protect a website?

SSL, short for Secure Sockets Layer, is a technology that can encrypt data transferred between end-users and the server. This prevents hackers from being able to access or “eavesdrop” on your activities. Websites protected by SSL start with “https://” in the address bar.

What are the problems with SSL?

Problems with your SSL certificate can cause many web browsers to block users from accessing your site, or to display a security warning message when your site is accessed.

What is SSL in Mobile?

The Secure Sockets Layer (SSL)—now technically known as Transport Layer Security (TLS)—is a common building block for encrypted communications between clients and servers. An application might use SSL incorrectly such that malicious entities may be able to intercept an app’s data over the network.

Are TLS and SSL the same?

Transport Layer Security (TLS) is the successor protocol to SSL. TLS is an improved version of SSL. It works in much the same way as the SSL, using encryption to protect the transfer of data and information. The two terms are often used interchangeably in the industry although SSL is still widely used.

Safety note: This is not a prescription or diagnosis. For severe symptoms, pregnancy danger signs, children with serious illness, chest pain, breathing difficulty, stroke-like weakness, or major injury, seek urgent care.

Which doctor may help?

Start with a registered doctor or the nearest qualified health center.

What to tell the doctor

Write when the problem started and how it changed.
Bring old prescriptions, investigation reports, and current medicines.
Write allergies, pregnancy status, diabetes, kidney/liver disease, and major past illnesses.
Bring one family member if the patient is weak, elderly, confused, or a child.

Questions to ask

What is the most likely cause of my symptoms?
Which danger signs mean I should go to hospital quickly?
Which tests are necessary now, and which can wait?
How should I take medicines safely and what side effects should I watch for?
When should I come for follow-up?

Tests to discuss

Vital signs: temperature, pulse, blood pressure, oxygen saturation
Basic physical examination by a clinician
CBC, urine test, blood sugar, or imaging only when clinically needed

Avoid these mistakes

Do not use antibiotics, steroid tablets/injections, or strong painkillers without proper medical advice.
Do not hide pregnancy, kidney disease, ulcer, allergy, or blood thinner use.
Do not delay emergency care when danger signs are present.

Medicine safety and first-aid guide

This section is for patient education only. It does not replace a doctor, pharmacist, or emergency care.

Safe first steps

Avoid heavy lifting, sudden bending, and prolonged bed rest.
Use comfortable posture and gentle movement as tolerated.
Discuss physiotherapy, X-ray, or MRI only when clinically needed.

OTC medicine safety

For mild back pain, pain-relief medicine may be discussed with a doctor or pharmacist.
Avoid repeated painkiller use if you have kidney disease, stomach ulcer, uncontrolled blood pressure, or are taking blood thinners.

Avoid these mistakes

Do not start antibiotics without a proper medical decision.
Do not use steroid tablets or injections casually for quick relief.
Do not delay emergency care because of home remedies.

Get urgent help if

Back pain with leg weakness, numbness around private area, loss of urine/stool control, fever, cancer history, or major injury needs urgent care.

Medicine names, dose, and timing must be decided by a qualified clinician or pharmacist after checking age, pregnancy, allergy, other diseases, and current medicines.

For rural patients and family caregivers

Patient health record and symptom diary

Write your symptoms, medicines already taken, test results, and questions before visiting a doctor. This note stays on your device unless you print or copy it.

Doctor to discuss: Doctor / qualified healthcare provider

Tests to discuss with doctor

Basic vital signs: temperature, pulse, blood pressure, oxygen level if needed
Relevant blood, urine, imaging, or specialist tests only after clinical assessment

Questions to ask

What is the most likely cause of my symptoms?
Which warning signs mean I should go to emergency care?
Which tests are really needed now?
Which medicines are safe for my age, pregnancy status, allergy, kidney/liver/stomach condition, and current medicines?

Emergency warning signs such as chest pain, severe breathing difficulty, sudden weakness, confusion, severe dehydration, major injury, or loss of bladder/bowel control need urgent medical care. Do not wait for online information.

Go to emergency care if you notice:

Severe or rapidly worsening symptoms
Breathing difficulty, chest pain, fainting, confusion, severe weakness, major injury, or severe dehydration

Doctor / service to discuss: Qualified healthcare provider; specialist depends on symptoms and examination.

Step 1
Check danger signs first
If danger signs are present, seek emergency care and do not wait for online information.
Step 2
Record the symptom story
Write when symptoms started, severity, medicines already taken, allergies, pregnancy status, and test results.
Step 3
Visit a qualified clinician
A doctor, nurse, or qualified healthcare provider can examine you and decide which tests or treatment are needed.
Step 4
Do only useful tests
Do tests after clinical assessment. Avoid unnecessary tests, random antibiotics, or repeated medicines without diagnosis.
Step 5
Follow up and return early if worse
If symptoms worsen, new warning signs appear, or treatment is not helping, return for review quickly.

Rural patient practical tips

Take a written symptom diary and all previous prescriptions/test reports.
Do not hide medicines already taken, even herbal or over-the-counter medicines.
Ask which warning signs mean urgent referral to hospital.

This roadmap is for education. A real diagnosis and treatment plan requires history, examination, and clinical judgment.

RX Patient Help

Ask a health question safely

Write your symptom story. A health professional or site editor can review it before any answer is prepared. This box is not for emergency care.

Emergency first: Severe chest pain, breathing trouble, unconsciousness, stroke signs, severe injury, heavy bleeding, or rapidly worsening symptoms need urgent local medical care now.

Frequently Asked Questions

What is SSL?

Secure Socket Layer (SSL) is the most used internet security cryptographic protocol before Transport Layer Security (TLS) was released in 1990. However, the SSL protocol has been discontinued, but the TLS has now adopted it. Most people call it SSL. SSL provides a secure link between two devices or computers linked to the internet or the internal network.

What is TLS?

TLS is a popular security protocol designed for Internet communication to enhance privacy and data security. It is generally used to encrypt communication among web packages and servers, including a web browser loading page. It can be used for encrypting different voice messages for texts and IPs. It was introduced by the Internet Technology Task Force (IETF) of the International Standards Organization (ISO), which launched the primary protocol in 1999. In 2018, the latest version was released and contained TLS 1.3.

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SSL (Secure Sockets Layer)

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