How does TLS work to secure your data

Every time users log in to a website, access a cloud application, send information online, or connect to a remote system, sensitive data travels across networks that may be exposed to potential threats. Without appropriate protections, attackers could intercept or manipulate that information while it is in transit. Transport Layer Security (TLS) is one of the most widely used technologies for protecting data as it moves between systems. It helps ensure that information remains private, authentic, and unchanged during transmission.

What is TLS?

TLS, or Transport Layer Security, is a cryptographic protocol that secures communications between devices and applications. Its primary purpose is to protect data while it travels across a network.

TLS is commonly used to secure:

• Websites
• Cloud applications
• Email services
• APIs
• VPN connections
• Remote access platforms
• Online transactions

Most secure internet traffic today relies on TLS.

Why is TLS important?

Data transmitted across networks may be vulnerable to interception, eavesdropping, or manipulation.

TLS helps organizations:

• Protect sensitive information
• Verify identities
• Prevent unauthorized access
• Reduce the risk of data tampering
• Support compliance requirements
• Build trust with users and customers

Without TLS, many online services would be significantly less secure.

How TLS works

TLS uses a combination of encryption, authentication, and integrity checks to secure communications. At a high level, the process follows several steps.

1. A connection is initiated

A client, such as a web browser or application, attempts to connect to a server. The client indicates that it wants to establish a secure TLS session.

2. The server presents its certificate

The server provides a digital certificate containing information about its identity. This certificate is issued by a trusted Certificate Authority (CA).

The client verifies that:

• The certificate is valid
• The certificate has not expired
• The certificate belongs to the intended server

This helps prevent impersonation attacks.

3. A secure session is established

The client and server perform a process known as a TLS handshake.

During the handshake:

• Cryptographic algorithms are negotiated
• Encryption methods are selected
• Session keys are generated

These keys are used to secure the communication.

4. Data is encrypted and transmitted

Once the handshake is complete, data can be exchanged securely. Information is encrypted before transmission and decrypted only by the intended recipient. Anyone intercepting the traffic would see only encrypted data.

What is the TLS handshake?

The TLS handshake is the process that establishes trust between two systems.

Its objectives include:

• Authenticating the server
• Negotiating encryption methods
• Creating secure session keys
• Preparing a protected communication channel

Although the process occurs in milliseconds, it is one of the most important security mechanisms on the internet.

TLS vs. SSL

TLS is often associated with SSL (Secure Sockets Layer). However, SSL is an older technology that has largely been replaced by TLS. Today, when people refer to "SSL certificates," they are typically referring to certificates used with modern TLS protocols. Current security best practices recommend using TLS rather than legacy SSL versions.

What security does TLS provide?

TLS delivers three key security benefits. These protections work together to make online communication safer by keeping data private, verifying trusted connections, and helping prevent tampering during transmission.

Confidentiality

Encryption prevents unauthorized parties from reading transmitted data. TLS helps keep information private while it moves between a user’s device and a server, such as login details, payment data, or business communications. Even if traffic is intercepted, the encrypted content is designed to remain unreadable without the correct keys. 

Authentication

Certificates help verify that users are communicating with legitimate systems. During a TLS connection, the server presents a digital certificate that confirms its identity and helps prevent users from connecting to fake or malicious websites. This builds trust between the user’s device and the service they are trying to access. 

Integrity

Integrity checks help detect whether data has been modified during transmission. TLS uses cryptographic methods to confirm that information arrives as it was originally sent, without being altered by attackers or network errors. Together, these protections help secure digital communications.

Common uses of TLS

TLS is used throughout modern IT environments.

Examples include:

• HTTPS websites
• Online banking
• Software-as-a-Service (SaaS) platforms
• Video conferencing tools
• Cloud services
• Secure email systems
• Enterprise applications

Most users interact with TLS-protected services many times each day.

How TeamViewer uses secure communications

Secure remote access depends on protecting data while it moves between devices. TeamViewer uses industry-standard encryption and secure communication mechanisms to help protect remote sessions, file transfers, and connections between endpoints. Secure communication protocols play an important role in ensuring that data exchanged during remote access sessions remains protected against interception and unauthorized access. For organizations supporting remote work and distributed operations, secure communications are a critical component of maintaining trust and protecting business information.

Best practices for TLS security

Organizations can strengthen TLS security by:

• Using current TLS versions
• Maintaining valid certificates
• Removing outdated protocols
• Applying software updates
• Monitoring certificate expiration dates
• Following established security standards

Proper configuration is essential to achieving the full benefits of TLS.