Transport Layer Security (TLS) and its predecessor Secure Sockets Layer (SSL), are cryptographic protocols designed to provide communications security over a computer network. They use X.509 certificates and asymmetric cryptography to authenticate the counterparty with whom they are communicating, and to negotiate a symmetric key. This session key is then used to encrypt data flowing between the parties.
SSL and TLS provide data encryption to ensure confidentiality, data integrity to ensure there has been no tampering or corruption of data, and authentication to ensure communication is between the intended parties.
Why SSL and TLS are Used
SSL and TLS protocols are essential to internet security and privacy. They protect sensitive information such as:
- Credit card details when consumers make online transactions
- Login credentials when accessing web-based email, banking portals or cloud-based services
- Medical and health data records
- Intellectual property and proprietary business data
Without SSL/TLS, data sent over the internet could be read or modified by attackers relatively easily. These protocols make eavesdropping, tampering and forging very difficult.
Brief History of SSL and TLS Protocols
- 1994 – Netscape developed SSL protocol Version 1.0 but it was never released.
- 1995 – SSL Version 2.0 released with enhanced security features
- 1996 – SSL Version 3.0 released to plug security vulnerabilities in SSLv2
- 1999 – TLS Version 1.0 finalized in RFC 2246 based on SSL Version 3.0
- 2006 – TLS Version 1.1 released with protections against padding oracle attacks
- 2008 – TLS Version 1.2 released with improved flexibility and enhanced security
- 2018 – TLS 1.3 published built for modern internet needs
Over the years, TLS has evolved to provide improved defenses against the latest data interception and hacking techniques that emerge.
How SSL and TLS Protocols Work
The SSL/TLS handshake process establishes a secure session link with authentication, encryption algorithms and keys before any application data is transmitted:
- Client Hello – Client sends supported TLS version, cipher suites and compression methods
- Server Hello – Server responds with chosen TLS version, cipher suite and compression methods
- Server Certificate – Server sends public key certificate to prove its identity
- Client Key Exchange – Client generates session key and encrypts with server’s public key to share
- Change Cipher Spec Protocol – Change cipher suite to previously agreed specifications
- Finish – Client and server notify that further communications will use the session key and selected ciphers for encryption.
All subsequent user data flowing via the session is encrypted with the session key negotiated during the handshake.
SSL digital certificates are used extensively in ecommerce and online transactions to establish trust between two parties communicating over the internet.
- Issued by certificate authorities that validate the organization’s identity
- Bind a public key with business details like domain name for authentication
- Helps users identify legitimate websites and safe routes for secure data transmission
The certificate lifecycle includes issuance, renewal and revocation when no longer needed.
Use of SSL and TLS Today
The TLS protocol is still the backbone securing internet communication across websites, apps, servers and internet infrastructure that transmit sensitive data like:
- Ecommerce checkouts and payment gateways
- Email, messaging and video chat applications
- Virtual private network (VPN) connections
- Application programming interfaces (APIs)
- System administration controls like SSH
Key Takeaway: SSL and TLS protocols enable trusted communication between two parties over the internet by allowing mutual authentication, data encryption, and data integrity checks to safeguard sensitive information during transit.
SSL (Secure Sockets Layer) and its successor TLS (Transport Layer Security) are fundamental internet encryption protocols first developed by Netscape to enable secure data transfer. They authenticate communicating parties, negotiate encryption keys and algorithms to encrypt user data transmitted.
Over the decades, SSL & TLS have evolved to counter sophisticated hacking threats that emerge to attack vulnerabilities. TLS 1.3 is the latest version using new cipher suites and cryptographic techniques for cutting edge protection.
These protocols form the backbone of security for any internet transmission of sensitive or confidential data – including credit cards, health records, credentials and proprietary information. Understanding SSL and TLS is still pivotal for organizations and users to maintain privacy and trust in the digital economy.
Frequently Asked Questions
- What is SSL?
SSL (Secure Sockets Layer) is an encryption protocol for securing data sent between a web server and a browser. It was introduced by Netscape in the mid-1990s to enable secure internet communications and transactions. The latest general standard version is known as TLS (Transport Layer Security).
- What does TLS stand for?
TLS stands for Transport Layer Security. It is a cryptographic protocol that provides end-to-end data security for internet communications and is the successor to SSL (Secure Sockets Layer).
- Why is SSL important?
SSL is important because it establishes an encrypted link enabling secure communication over the internet for transmitting confidential data like credit cards, login credentials and health records securely without risk of eavesdropping or tampering attacks.
- What is SSL used for?
Common uses of SSL today include securing web browsing, ecommerce sites and checkouts, login authentication, APIs and database connections transmitting private data. It helps verify authenticity and trust between parties communicating over a network.
- What’s the difference between SSL and TLS
The main differences are SSL was originally developed by Netscape, while TLS is standardized by the IETF. TLS 1.0 was based on SSL 3.0 but has enhanced ability to negotiate encryption keys and crypto algorithms. TLS is more modern offering better security.
- Is TLS better than SSL?
Yes, Transport Layer Security (TLS) is considered better than Secure Sockets Layer (SSL). TLS is constantly evolving with stronger data encryption cipher suites to address latest internet hacking threats. Most servers use TLS by default rather than the older SSL nowadays.
- Is TLS the same as SSL?
TLS is largely based on SSL and they serve fundamentally the same function using similar processes in establishing secure network sessions for communication partners. However, TLS has evolved capabilities so offers security improvements over SSL – hence TLS 1.3 is the latest industry standard rather than SSL.
- Can TLS use SSL certificates?
Yes, TLS can use SSL certificates for setting up end-to-end encrypted sessions. A public key infrastructure and SSL certificates help TLS to authenticate identities on each end of a network connection enabling private data to transmit securely.
- Is TLS more secure than HTTPS?
TLS is essentially part of what makes up HTTPS – TLS establishes the secure encrypted session for data transfer whereas HTTPS is the protocol for secure web browsing. Both are very secure, HTTPS leverages TLS encryption plus certificate verification for a trusted browsing experience.
- What are examples of SSL and TLS?
Common examples that use the SSL or TLS protocol for security include websites accessed via HTTPS, VPN connections for remote access to networks, secure email services like Gmail TLS, payment gateways encrypting credit card transactions, chat apps like WhatsApp, database connections and application programming interfaces (API).
- Why is SSL important for API security?
For APIs transmitting sensitive data, SSL is extremely important for security by encrypting data in transit and preventing unauthorized access by third parties. It can also authenticate legitimate callers of the API. SSL protects APIs accessed over internet, cloud or other distributed computing systems where risk of attack is higher.
- What SSL certificate is best?
Some of the most highly trusted SSL certificates are the Extended Validation (EV) certificates provided by certificate authorities like DigiCert, GeoTrust, Global Sign and Thawte. EV SSL meets rigorous verification and displays green browser address bar for trusted sites.
- How does SSL encryption work?
SSL encryption works through a handshake process that establishes an encrypted session between client and server using an agreed algorithm like AES or RC4 to symmetrically encrypt messages with a shared key for secure transmission over a network. Public-key cryptography encrypts the symmetric key exchange during SSL handshake process.
- Is 128 or 256 bit SSL better?
256-bit SSL is better than 128-bit SSL encryption. The larger key size makes it exponentially harder to crack and thus more secure against brute force attacks trying to decrypt the communication. However 128-bit SSL is still standard and acceptable for many uses to balance security with efficiency.