Secure Sockets Layer (SSL) and Transport Layer Security (TLS) are both cryptographic protocols that help secure communications over a computer network. There are many similarities between the protocols used in SSL and TLS, so much so that many applications configure their implementation together as "SSL/TLS."
Both types of certificates are machine identities that are used for data encryption and authorization and verification. But SSL and TLS do differ from one another in some respects.
Machine identities have two distinct purposes:
- Identity Confirmation and Validation: Information contained in TLS and SSL certificates authenticates and verifies the legitimacy of a website or host's identity. By inspecting the padlock symbol or trust mark, you can view the certificate chain, confirming the source of the certificate's issuance.
- Securing Data: The role of TLS and SSL certificates extends to data encryption. This ensures that any sensitive data transmitted through the website is encoded in such a way that only the designated recipient can decode and read it, preventing unauthorized access or interception.
- A TLS/SSL certificate is most reliable when issued by a trusted Certificate Authority (CA). The CA has to follow very strict rules and policies about who may or may not receive an SSL Certificate. So, when you have a valid SSL certificate from a trusted CA, there is a higher degree of trust.
What is SSL?
SSL, an acronym for Secure Sockets Layer, was created by Netscape in the 1990s as a method to safeguard online communications. Its main role in the modern digital landscape is to encrypt data exchanged between two entities, thereby mitigating potential security vulnerabilities in these communications. This protocol finds its application in numerous areas such as email, internet surfing, and the transfer of files.
The initial release of the SSL protocol (SSL 1.0) occurred in 1995, but it was not made publicly available due to the identification of security vulnerabilities. Following this, a second version (SSL 2.0) emerged in 1996, which also remained unreleased to the public due to similar security concerns. In 1996, the SSL 3.0, third and most recent iteration of the SSL protocol was introduced. This version has become the most extensively adopted variant of the SSL protocol.
TLS has replaced SSL certificates in many instances, yet SSL continues to be employed in certain applications.
What is TLS?
While Secure Sockets Layer (SSL) laid the foundation for secure online communication, its successor, Transport Layer Security (TLS), offers a robust upgrade. TLS fixes known SSL vulnerabilities and significantly enhances authentication and encryption. Both protocols create secure channels, but TLS boasts stronger algorithms, improved certificate validation, and a more efficient handshake process. These advancements make TLS the clear choice for modern web applications and secure internet communication.
Introduced in 1999, TLS 1.0 was the first version of the TLS protocol, soon followed by TLS 1.1 and then TLS 1.2. TLS 1.2, launched in 2008, remains the most prevalently used version of the protocol as of the date of this article.
The latest version, TLS 1.3, is rapidly emerging as the standard encryption protocol for the internet. The National Institute of Standards in Technology (NIST) mandates that all government TLS servers and clients support TLS 1.2 with FIPS-compliant cipher suites. Additionally, they advised agencies to prepare for migrating to TLS 1.3 by January 1, 2024.
SSL vs TLS: Similarities
SSL and TLS are protocols that protect data being sent between servers, applications, users, and systems. They make sure that two parties on a network can share information safely. Similarities between SSL and TLS include:
Terminology: Even though TLS has replaced SSL, the term SSL is often used interchangeably with TLS. Usually, when people mention SSL or SSL/TLS, they are actually referring to the TLS protocol and its certificates.
Purpose: The main purpose of TLS, like its predecessor SSL, is to provide a way for secure communication, involving encryption and authentication. Both protocols utilize digital certificates to manage the initial connection setup, enabling encrypted communication between a web browser and a server.
HTTP/HTTPS: HTTP is a set of rules for transferring data between a client and a server. HTTPS, on the other hand, is HTTP combined with SSL or TLS to make the connection secure.
Before your browser connects to a website, it checks the site's TLS or SSL certificate using TLS. These certificates are a mark of adherence to current security standards. You can spot these certificates in the browser's address bar: a secure, encrypted connection will show 'https://' instead of 'http://', where the extra 's' signifies security.
SSL vs TLS: Differences
SSL and TLS, though designed with the same objective, exhibit several notable differences.
Cipher Suite Usage
A primary distinction lies in the cipher suites they employ. These suites are collections of algorithms that encrypt data. SSL and TLS use distinct cipher suites, with TLS, especially in its 1.3 version, enhancing encryption algorithms, like introducing perfect forward secrecy.
Handling of Alert Messages
The protocols differ in their treatment of alert messages, which communicate errors and warnings. In SSL, these messages are unencrypted and can be intercepted. TLS, however, encrypts alert messages, making them readable only to the communicating parties.
Record Protocol Differences
SSL and TLS utilize different protocols for encapsulating data exchange. SSL employs its own SSL record protocol, originally developed by Netscape. Conversely, TLS uses the standardized TLS record protocol, crafted by the IETF.
The process for establishing a secure communication channel, known as the handshake, also varies. SSL completes this process through a "full handshake" and an "abbreviated handshake." TLS handshakes simplify this with a single-step "full handshake."
Message Authentication Approaches
The method of confirming the integrity of transmitted data, or message authentication, differs between the two. A message is authenticated via SSL by utilizing a brief piece of data known as a message authentication code (MAC), which ensures a message's validity and integrity. TLS employs a keyed-hash message authentication code (HMAC), or MAC, which is generated using a secret cryptographic key and a cryptographic hash function. SSL uses the MD5 algorithm for this purpose, while TLS opts for the more secure SHA-256 algorithm. The key distinction is MD5's susceptibility to collision attacks, a vulnerability absent in SHA-256.
Perfect Forward Secrecy
Perfect Forward Secrecy is a crucial feature in the context of Transport Layer Security (TLS) protocols, enhancing the security of encrypted data. In TLS 1.3, the RSA key exchanges used by SSL were replaced with Diffie-Hellman key exchanges, which provide forward secrecy. It ensures that each session between a user and a server has a unique set of encryption keys. This means that even if a server's key is compromised in the future, past communications remain secure because they were encrypted with different keys. This feature of TLS protocols significantly strengthens the overall security of internet communications, making it a preferred choice for secure data transmission.
“By Program” or “Implicit” Security
TLS is frequently also referred to as "By Program" or "implicit" security since it requires a program to establish an unsafe connection first before using special commands to activate encryption. This is distinct from "By Port" or "explicit" security in SSL, or an explicit connection to a port that anticipates a session to commence with security negotiation.
Secure Your Digital Environment with Venafi TLS Protect
In conclusion, while understanding the differences between SSL and TLS is crucial, it's equally important to manage and secure your TLS certificates effectively. This is where Venafi TLS Protect comes in.
Why Choose Venafi TLS Protect?
- Automate and Simplify: Say goodbye to the complexities of manual certificate management. Automate the entire lifecycle of your TLS certificates and reduce the risk of human errors.
- Boost Your Security: Protect your organization from vulnerabilities associated with TLS certificates. Venafi's robust security measures prevent unauthorized issuance and misuse, keeping your digital environment safe.
- Stay Compliant, Stay Secure: Meet regulatory requirements effortlessly. Manage your certificates in compliance with industry standards and internal policies.
- Visibility at Your Fingertips: Gain centralized control over all your TLS certificates. With Venafi TLS Protect, oversee your digital security landscape from a single, intuitive dashboard.
- Scale with Confidence: Whether you're a small business or a large enterprise, Venafi TLS Protect scales to meet your needs, managing numerous certificates efficiently.
- Minimize Downtime: Avoid service interruptions and maintain customer trust. With automated renewals and proactive management, ensure your certificates are always up to date.
- Seamless Integration: Enhance your existing security tools with Venafi's seamless integration capabilities.
- Make Informed Decisions: Leverage detailed analytics and reports to make strategic decisions about your digital security.
Don't let certificate management be your blind spot. With Venafi TLS Protect, empower your organization with advanced automation, security, and compliance.
Ready to take control of your TLS certificates? Learn more about Venafi TLS Protect and how it can fortify your digital security. Let's make your digital environment more secure and compliant today!
(This post has been updated. It was originally published on February 12, 2019.)