What is a Cipher Suite and Why Does it Matter? 

Without the proper security measures, hackers can intercept your website’s data, including customer information, payment details, and login credentials.  

Adding SSL/TLS protocol to your website can ensure that cyberattacks cannot compromise your site and the user’s browser. But what manages the intricate details of the SSL/TLS encryption process? 

Cipher suites work behind the SSL/TLS protocol scenes. They ensure that your online communication is secured and protected from any threats. By the end of this blog, you’ll learn more about what cipher suites are, why they’re critical for your website’s security, and how to configure them.   

What is a cipher suite?  

A cipher suite is a package of security tools that keeps online communication private and safe between your web browser and the websites you visit. It includes ways to encrypt data, verify identities, and securely exchange keys, 

In cryptology, a cipher is an algorithm for encrypting and decrypting data. It outlines the general principles of securing a network through SSL/TLS.    

A cipher suite is composed of several ciphers with different cryptographic functions, such as key generation and authentication. They’re basically a team of coders and decoders working together for you. 

When connecting to a website, your device and the website’s server negotiate the best cipher to use when communicating. This ensures that your sensitive information (passwords and credit card information) is protected during the data transmission.  

However, not all cipher suites have the same level of security. Some are outdated and vulnerable to attacks. This is why it’s crucial to use robust and up-to-date cipher suites to keep your website’s sensitive information safe. 

How cipher suites work in SSL/TLS protocols  

When you visit a secure website with HTTPS, your browser and the website’s browser establish a secure connection through the SSL/TLS handshake. 

Here’s how it works:   

1. Client hello. This is where the client sends a list of supported cipher suites to the server.   

2. Server hello. The web server chooses the most secure cipher suites supported by both client and server.   

3. Key exchange. The key exchange algorithm securely shares the encryption keys.   

4. Encryption. Data is encrypted using the selected encryption algorithm.   

5. Authentication and integrity. Authentication algorithms validate the connection, while hashing ensures data integrity.    

This process ensures that the handshake is quick, safe, and resistant to threats such as data breaches.   

What does a cipher suite look like? 

Note that a cipher suite looks different depending on the TLS version. The current standards nowadays are TLS 1.2 and 1.3. Although TLS 1.3 is the newer and more secure version, TLS version 1.2 is still widely used.   

Their difference is evident from the number of ciphers used and the length of their cipher suites. TLS 1.2 has 37 ciphers, while TLS 1.3 only has five. Here are some examples:   

• TLS 1.2 cipher suite  

TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384   

• TLS 1.3 cipher suite  

TLS_AES_256_GCM_SHA384  

Based on the sample provided, the TLS 1.3 cipher suite is shorter compared to TLS 1.2. But what makes it better compared to TLS 1.2? To better understand the given example, we’ll dive into what the series of letters and numbers mean.   

Components of a cipher suite  

A cipher suite is made up of four key components. 

The TLS 1.2 cipher suite consists of four ciphers: 

Key exchange algorithm  

A key exchange algorithm is a method that creates and exchanges secret keys between two or more parties. This process is performed during the handshake to ensure data confidentiality during file transfers. 

In the example given, the key exchange algorithm was represented by ECDHE or the Elliptic Curve Diffie Hellman Ephemeral, which outlines how the client and the server will exchange the keys.   

Other common algorithms include: 

• RSA. Uses the RSA algorithm for both key exchange and authentication. 

• Diffie-Hellman (DH). Allows two parties to jointly establish a shared secret over an insecure channel. 

• Elliptic Curve Diffie-Hellman (ECDH). A variant of DH that uses elliptic curve cryptography for better performance and security. 

Compared to other algorithms, ECDHE is much faster and offers stronger security.  While EDCHE and EDCH are nearly similar, ECDHE gives you the forward secrecy, while ECDH does not. EDCHE is the only one compatible with the Perfect Forward Secrecy (PFS) feature, which enables short-term, private key exchanges between clients and servers in SSL/TLS. 

Authentication algorithm  

Authentication algorithms are a set of rules used by a computer system to verify the identity of an entity. It checks if the entity that wants to connect to your website matches the password or unique code it gives before allowing access.  

In the example provided, the authentication algorithm is represented by the ECDSA or the Elliptic Curve Digital Algorithm. This digital signature shows the certificate type and helps the client verify that the website’s SSL is authentic.   

Aside from ECDSA, here are some common algorithms used for authentication:  

• Digital signature algorithm (DSA). This method uses a complex mathematical problem to create digital signatures. It’s like a unique fingerprint that proves the authenticity of a digital document or message. 

• Rivest-shamir-adleman (RSA). This algorithm is based on the difficulty of breaking down large numbers into their prime factors. It’s like a strong lock that’s almost impossible to crack, making it a popular choice for secure communication. 

Bulk data encryption algorithm 

Bulk encryption is a method where combined transmissions from several data streams are encrypted together. This method encrypts large amounts of data, making it almost impossible for anyone without a proper decryption algorithm to read.  

This cipher ensures that the data transmission between the client and server is secure from any data breach. AES_256_GCM is used to represent it in the example. 

Advanced encryption standard (AES) is the method commonly used for bulk data encryption due to its flexibility and compatibility across platforms.  However, aside from AES, there are other algorithms that can be used depending on the specific security requirements and performance needs.  

Symmetric-key algorithms: 

• Triple data encryption standard (3DES). It’s a more secure version compared to the older DES algorithm, but it’s slower compared to AES.  

• Blowfish. This is a fast and secure algorithm that is often used in software applications. 

• Twofish. This is also another strong algorithm that can be used as an alternative to AES.  

• Camellia. This is another strong and efficient key block cipher that provides a high level of security while being suitable for various applications.  

Message authentication code (MAC)  

A message authentication code (MAC) is used to verify both the integrity and authenticity of a message. It’s a short piece of data generated by a cryptographic function that takes a message and secret key as input.  

The MAC authentication code ensures data integrity, confirming that the data wasn’t tampered with during the transmission. It’s represented by the SHA384 in the example above.  

Common MAC algorithms:  

• Hash-based message authentication code (HMAC). This is a popular algorithm that utilizes a cryptographic hash function like SHA-256.  

• Cipher-based message authentication code (CMAC). This MAC algorithm is based on a block cipher like AES.  

• Poly1305. This is a modern MAC algorithm that is known for its speed and security.  

On the other hand, the newer TLS version TLS 1.3 cipher suite only uses two ciphers: the bulk data encryption and MAC algorithm. This is a more secure version than TLS 1.2 because it shortens the handshake process, as there’s no need to display the type of key exchange algorithm and authentication algorithm. It’s because TLS 1.3 only accepts the Ephemeral Diffie-Hellman method of key exchange.  

Why website owners should care about cipher suites  

Securing your website with modern cipher suites is important for several reasons. Here’s why:   

Protect user data  

Modern cipher suites permit encryption, which guarantees that any information shared between your website and its users cannot be read by unauthorized parties. Encryption protects sensitive data from hackers, including payment information, login credentials, and personal information.  

Meet compliance requirements  

Strict rules that regulate many sectors require secure data transfer. Heavy fines, legal repercussions, and harm to one’s reputation might result from noncompliance.  

Example of regulations:   

• GDPR – The General Data Protection Regulation requires business sectors to safeguard personal data for EU citizens. One of their key requirements is secure communication via HTTPS with a modern cipher.   

• PCI DSS – The Payment Card Industry Data Security Standard strongly mandates encryption for all payment-related data transfers.   

Build customer trust  

Consumers are more inclined to trust a website that clearly puts security first.  Using contemporary encryption techniques is indicated by a padlock icon or HTTPS in the browser’s address bar.  Once visitors see that on your site, they know they can trust you and are more likely to interact with your website.   

Best practices for configuring secure cipher suites  

Configuring secure cipher suites is crucial for safeguarding your website and users. Listed below are some of the best practices you can do to optimize your website’s security:  

Update SSL/TLS protocols  

The foundation of secure communication lies in using the up-to-date SSL/TLS protocols:  

Why it matters:   

TLS 1.0 and 1.1 are among the older versions that are susceptible to BEAST and POODLE attacks. The BEAST attack is a man-in-the-middle attack that exploits vulnerabilities in the older versions of SSL/TLS. Imagine this: you’re sending a secret letter to a friend. A BEAST attack is like a sneaky thief who intercepts your letter, reads it, and then sends it on to your friend, pretending nothing happened. The thief can do this by exploiting weaknesses in the way you’re sealing your letters. 

The POODLE, on the other hand, is nearly the same as a BEAST attack, but it’s harder to detect since it slowly peels away the layers of your secret letter, one layer at a time. By exploiting a weakness in the way you’re sealing your letters, the thief can uncover your secret message piece by piece. 

These old TLS protocols are inappropriate for today’s online security requirements because they lack the sophisticated security features included in more recent versions.  

What to do:   

Upgrade to TLS 1.3, the most recent version, which improves performance, removes unsafe techniques, and streamlines the handshake procedure. If TLS 1.3 isn’t supported yet, ensure you’re at least utilizing TLS 1.2, but switch as soon as you can.  

Choose strong TLS cipher suites  

Not all cipher suites are created equally. Some are outdated, which makes your website vulnerable.   

Why it matters:  

Weak cipher suites, like as ones that use MD5 or RC4, are prone to vulnerabilities, which can expose your website to attacks like hash collisions and ciphertext manipulation.  

Hash collisions happen when two different inputs produce the same hash value. Once this occurs, an attacker could potentially forge a document with different content containing the same digital signature.  

Meanwhile, ciphertext manipulation involves altering encrypted data. When decrypted, it produces a different message that can be exploited to inject malicious code or data into a system. 

What to do:  

Audit your server settings and disable obsolete or weak cipher suites. Focus on enabling strong algorithms, such as:  

• Key Exchange: ECDHE (Elliptic Curve Diffie-Hellman Ephemeral)  

• Authentication: RSA or ECDSA  

• Encryption: AES (GCM or CBC mode)  

• MAC/Hashing: SHA-256 or higher   

Test your configurations   

Even with strong settings, misconfigurations can lead to vulnerabilities. Testing ensures that your cipher suites are secure and implemented properly.    

Why it matters:  

Even with robust protocols and cipher suites installed, misconfigured settings can make your website susceptible to cyber-attacks such as hacking, data breaches, or malware infections. These problems are found through testing before they become liabilities.   

What to do:  

Use tools like:  

• SSL Labs. Provides a detailed report on your website’s SSL/TLS implementation, highlighting weaknesses and suggesting improvements.  

• Qualys SSL Test. A free tool that grades your setup and pinpoints areas that need attention.   

Partner with trusted providers  

It might be difficult to manage cipher suite setups, particularly for website owners without technical knowledge. Reputable companies make this easier by providing security solutions that are already configured.   

Why it matters:  

Your website will always be protected with the newest configurations if you work with a reputable provider. This reduces the time and effort needed to handle security on your own while minimizing threats.   

What to do:  

Choose a hosting provider like Domain.com, which offers built-in security measures, including:  

• Automatic protocol updates.  

• Pre-configured strong cipher suites.  

• Expert support to help you navigate security challenges.  

Secure your website with modern cipher suites today   

In summary, cipher suites are the backbone of secure online communication. They shield user data, ensure compliance, and build customer trust. By updating your configurations and following the best practices, you can protect your website from vulnerabilities and provide a safe, trustworthy experience for your customers.   

Ready to optimize your website security? Take the first step with Domain.com and explore more ways to protect your website with our robust security solutions.