SSL vs TLS: What's the Difference?

In today's digital era, ensuring the security of network communication is of utmost importance. SSL (Secure Sockets Layer) and TLS (Transport Layer Security) are two widely used protocols for encrypting and securing data during transmission over networks. SSL (Secure Sockets Layer) and TLS (Transport Layer Security) are encryption protocols used to secure data transmission over networks. They establish a secure communication channel, ensuring that data remains confidential, unaltered, and protected from unauthorized access during transmission.

What are SSL and TTL?

SSL (Secure Sockets Layer) is a cryptographic protocol that provides secure communication over a computer network, primarily on the Internet. It ensures that the data transmitted between a client (such as a web browser) and a server (such as a website) is encrypted and protected from eavesdropping, tampering, or forgery. SSL has been largely replaced by its successor, TLS (Transport Layer Security), but the term SSL is still commonly used to refer to both protocols.

TTL (Time to Live) is a concept used in various networking technologies, including IP (Internet Protocol) and DNS (Domain Name System). It represents the duration for which a piece of information, such as a packet or a DNS record, is considered valid before it is discarded or refreshed. In IP, TTL is a value that indicates the maximum number of hops (intermediate devices, such as routers) that a packet can traverse before being discarded. In DNS, TTL specifies the time in seconds that a DNS resolver should cache a DNS record before querying the DNS server again for updated information.

How do SSL and TLS Work?

TLS (Transport Layer Security) and SSL (Secure Sockets Layer) are encryption protocols used to secure network communication. They share similar working principles, which are explained below.

The working principles of TLS and SSL are as follows:

• Handshake Phase:

1. The client verifies the validity and authenticity of the server's digital certificate. This includes checking if the certificate's signature is valid if it has expired, and if it matches the server's domain name.
2. If the verification fails, the client may issue a warning or terminate the connection.

• Certificate Verification:

1. The client verifies the validity and authenticity of the server's digital certificate. This includes checking if the certificate's signature is valid if it has expired, and if it matches the server's domain name.
2. If the verification fails, the client may issue a warning or terminate the connection.

• Key Exchange:

1. The client generates a random symmetric key and encrypts it using the server's public key.
2. The server decrypts the encrypted key using its private key.

• Data Transmission:

1. The client and server use the negotiated symmetric key for data encryption and decryption.
2. Data is encrypted using the symmetric key during transmission, ensuring data confidentiality and integrity.

TLS and SSL use a combination of asymmetric encryption and symmetric encryption. Asymmetric encryption is used to securely exchange the symmetric key, while symmetric encryption is used for actual data transmission. This combination provides higher efficiency and security.

How do SSL and TLS Protect Data?

TLS (Transport Layer Security) and SSL (Secure Sockets Layer) protect data through the following mechanisms:

• Encryption: TLS and SSL use encryption algorithms to encrypt data, making it unreadable during transmission. This means that even if someone intercepts the data packets, they cannot directly access the sensitive information. Encryption ensures data confidentiality and only the intended recipient with the correct key can decrypt and read the data.
• Authentication: TLS and SSL use digital certificates to authenticate the identities of the communicating parties. The server presents a digital certificate to prove its identity and provides a public key for the client to use. The client can verify the validity and authenticity of the certificate, ensuring communication with the correct server and preventing man-in-the-middle attacks.
• Integrity Protection: TLS and SSL use Message Authentication Codes (MAC) or digital signatures to protect data integrity. During data transmission, a MAC or digital signature is computed for the data, allowing the recipient to verify if the data has been tampered with. If any modifications are detected, the recipient rejects the tampered data.
• Key Exchange: TLS and SSL use asymmetric encryption algorithms for secure key exchange to share a symmetric key. Asymmetric encryption algorithms use a public key and a private key, where the public key is used to encrypt the symmetric key, and the private key is used to decrypt it. This ensures that only the intended recipient with the correct private key can decrypt the symmetric key and use it for encryption and decryption of data.

Through these security mechanisms, TLS and SSL ensure data confidentiality, integrity, and authentication during transmission. This makes network communication more secure, mitigating risks of eavesdropping, tampering, or impersonation of data.

What is the Difference between SSL and TLS?

The main differences between TLS (Transport Layer Security) and SSL (Secure Sockets Layer) are as follows:

• Versions: SSL was the earliest secure protocol, initially developed by Netscape. Over time, different versions of SSL were released, such as SSL 2.0 and SSL 3.0. However, SSL 3.0 has been deprecated due to security vulnerabilities. TLS is the successor of SSL, with versions including TLS 1.0, TLS 1.1, TLS 1.2, and TLS 1.3. TLS 1.3 is the latest and most secure version.
• Security: The security of TLS and SSL largely depends on their versions. TLS 1.3 offers stronger security compared to earlier versions and SSL, incorporating more robust encryption algorithms and stricter security protocols. TLS 1.3 also addresses security vulnerabilities present in earlier versions.
• Handshake Process: The handshake process in TLS and SSL has been improved in TLS 1.3 to enhance performance and security. The handshake process in TLS 1.3 is simplified, reducing round trips and supporting zero round-trip time (0-RTT) handshake, thereby speeding up the connection establishment.
• Supported Algorithms: TLS and SSL support different encryption algorithms and key exchange methods. TLS 1.3 enforces the use of more secure encryption algorithms such as AES-GCM and ChaCha20-Poly1305, and no longer supports some weaker algorithms.

Despite these differences, TLS and SSL share the same goals and basic principles of protecting network communication through encryption and authentication. TLS is widely used, while SSL is gradually being phased out as TLS provides stronger and more secure protection mechanisms.

Should I Choose SSL or TLS?

In modern network communication, it is recommended to use TLS (Transport Layer Security) instead of SSL (Secure Sockets Layer). Here are a few reasons to choose TLS:

• Security: The latest versions of TLS (such as TLS 1.3) provide stronger security and address some of the security vulnerabilities present in SSL. TLS 1.3 incorporates stronger encryption algorithms and stricter security protocols, offering a higher level of protection.
• Compatibility: Most modern browsers and applications have already transitioned to TLS and are gradually phasing out support for SSL. Using TLS ensures compatibility with the latest security standards and better interoperability.
• Performance: TLS 1.3 has improved the handshake process, reducing round trips and speeding up connection establishment. It also supports zero round-trip time (0-RTT) handshake, further enhancing connection speed.
• Future development: TLS is the successor to SSL and is a more modern and continuously evolving protocol. The latest versions of TLS will continue to be improved and enhanced to meet evolving security needs.

However, in certain specific cases, there may still be a need to use SSL, such as when communicating with older systems or devices that only support older SSL versions. Nevertheless, if there is a choice, it is recommended to use TLS for higher levels of security and performance.

EdgeOne's Support for SSL and TLS

When HTTPS access is enabled for your website, EdgeOne supports multiple SSL/TLS versions to ensure compatibility with different user terminals by default. Normally, you do not need to modify this configuration. However, if your website requires a high level of security and you need to prevent users from accessing your website through less secure SSL/TLS versions, you can customize this configuration by specifying the required SSL/TLS versions.