SSL encryption

SSL encryption stands for “Secure Sockets Layer” and is a security protocol that was developed to encrypt and secure data that is transmitted over the Internet.

This protocol enables data to be transmitted between two systems, for example a web browser and a web server, in encrypted form so that it is protected against unauthorized access.

Importance for security on the Internet

The importance of SSL encryption for Internet security cannot be overestimated. It protects sensitive information such as credit card numbers, personal data and login information from hackers and identity thieves.

Difference between SSL and TLS

SSL was largely replaced by TLS (Transport Layer Security), which is considered the successor to SSL. Although both protocols function similarly, TLS offers improved security features and is now used as the standard for secure communication on the Internet.

Feature SSL TLS
Encryption Basic encryption Advanced encryption
Security Lower compared to TLS Higher
Version number 1.0, 2.0, 3.0 1.0, 1.1, 1.2, 1.3

How SSL encryption works

SSL encryption uses a combination of asymmetric and symmetric encryption to ensure secure data transmission. Asymmetric encryption uses two keys – a public and a private key – for encryption and decryption. This is generally used to enable secure key exchange. Once the secure channel is established, SSL uses symmetric encryption because it is less computationally intensive and data can be encrypted faster.

SSL handshake and key exchange

The SSL handshake is a procedure that is used at the start of an SSL/TLS connection. It involves several steps in which the parties involved confirm their identity and negotiate a common encryption key. Here are the main phases of the handshake:

  1. ClientHello and ServerHello:Exchange of protocol versions, random numbers and other session specifications.
  2. Certificate presentation:The server sends its SSL certificate to the client for verification.
  3. Key exchange:The parties agree on encryption methods and exchange key information.
  4. Completion and confirmation:The session is encrypted and begins with secure communication.

Role of SSL certificates

SSL certificates play a crucial role in the SSL handshake. They contain the public key and are used to identify the server. Certificates are issued by certification authorities (CAs), which confirm the identity of the certificate holder.

  • Trust anchor: Trust in the certificate is based on trust in the issuing CA.
  • Validity check: The client checks the validity of the certificate, including expiration date and issuer.

Advantages of SSL encryption

SSL encryption is crucial for the protection of sensitive data. Data such as credit card numbers, social security numbers and login information is protected from access by third parties by being transmitted in encrypted form.

Building trust with website visitors

The use of SSL certificates increases visitors’ trust in a website. A visible sign of this is the lock symbol in the address bar of the browser, which indicates that a connection is secure.

Improvement of the search engine ranking

Google has confirmed that websites that use HTTPS will be favored in search results. This means that SSL encryption not only improves security, but can also contribute to the SEO performance of a website.

Summary of the advantages:

Advantage Description
Protection of sensitive data Prevents the theft of data such as credit card numbers and personal information.
Building trust with website visitors Visible lock symbol in the browser indicates a secure connection.
Improvement of the search engine ranking HTTPS websites may receive a ranking advantage in search engines such as Google.

Types of SSL certificates

SSL certificates come in different types, which differ in terms of validation level and intended use. Here are the most common types of SSL certificates:

Domain Validated (DV) SSL Certificates

These certificates offer a basic validation in which only the control over the domain is verified. They are issued quickly and cost less, but offer a lower level of confidence.

Organization Validated (OV) SSL Certificates

OV certificates offer a medium security level. They validate not only the ownership of the domain, but also the existence and identity of the organization. This requires stricter verification by the issuing CA.

Extended Validation (EV) SSL certificates

EV certificates represent the highest level of validation. They require a comprehensive check of the organization by the CA. Websites with EV certificates often show a green address bar in the browser, which is a strong signal of trust for visitors.

Wildcard SSL certificates

Wildcard certificates make it possible to secure an unlimited number of subdomains under one main domain. This is particularly useful for large companies or organizations with many subdomains.

Multi-Domain SSL Certificates

These certificates, also known as SAN (Subject Alternative Name) certificates, make it possible to secure several domain names with a single certificate. They are flexible and cost-effective for organizations that own multiple domain names.

Comparison of SSL certificate types:

Certificate type Validation level Suitable for
DP Low Small websites, blogs
OV Medium Company, e-commerce sites
EV High Banks, financial institutions
Wildcard Variable (based on the base certificate) Companies with many subdomains
Multi-Domain Variable (based on the base certificate) Organizations with multiple domains

Setting up SSL encryption

Setting up SSL encryption is an essential step in ensuring the security of a website. This process involves several important steps:

Purchase of an SSL certificate

  1. Selecting the right type of certificate:Choose one of the certificates described above depending on the needs of your website.
  2. Purchase from the certifier:Choose a trustworthy certification authority (CA) and purchase the certificate there. Prices and offers may vary.

Installing the SSL certificate on the web server

  1. Generation of a CSR (Certificate Signing Request):This is a data block that contains your public key and organization information.
  2. Submitting the CSR to the CA:After the data has been checked by the CA, your SSL certificate is issued.
  3. Installing the certificate on the server:Follow the instructions of your hosting provider to install the certificate correctly.

Configuration of the website for HTTPS

  1. Update the website configuration:Make sure that all connections run via HTTPS.
  2. Test the configuration:Check whether HTTPS is set up correctly and the website is accessible.

Redirection from HTTP to HTTPS

  1. Set up HTTP to HTTPS redirects:Make sure that all requests to the HTTP version of your website are redirected to HTTPS.

Checklist for the facility:

Step Description
Select and acquire a certificate According to the requirements and the type of website
Generate and submit CSR Provide the necessary data and send it to the CA
Install certificate On the web server according to the host’s instructions
HTTPS in the website configuration Ensure that all connections are handled via HTTPS
HTTP to HTTPS redirects Set up automatic forwarding from HTTP to HTTPS

Common problems and solutions

The implementation of SSL can occasionally lead to technical challenges. Here are some common problems and their solutions:

Fix mixed content

If an HTTPS page loads resources (such as scripts, images or stylesheets) via HTTP, this is referred to as “mixed content”. This can compromise security and trigger warning messages in the browser.

  • Solution: Make sure that all resources on the page are loaded via HTTPS. Then check the source code of your website and update all URLs to secure connections.

Detect and rectify SSL connection errors

SSL connection errors can occur due to various problems, including expired certificates, incorrect server configurations or incompatible protocol versions.

  • Solution: Check the validity of your SSL certificate, the configuration of the web server and make sure that the latest TLS versions are supported.

Regular renewal of the SSL certificate

SSL certificates have an expiration date. If the certificate expires, visitors to your website will be warned of an insecure connection.

  • Solution: Renew your certificates in good time. Many hosting providers offer automatic renewal services that can be helpful.

Ensure compatibility with older browsers and systems

Some older browsers do not support modern SSL/TLS protocols. This can result in users not being able to access an encrypted page.

  • Solution: While you should always strive to use current protocols and encryption techniques, it may be necessary to support certain older encryption methods to ensure compatibility.

Troubleshooting table:

Problem Solution
Mixed contents Load all resources via HTTPS
SSL connection error Check certificate, adjust server configuration, update TLS versions
Certificate renewal Use automatic renewal options, comply with renewal deadlines
Browser compatibility Check encryption support for older browsers and adapt if necessary


SSL encryption plays a crucial role in securing the Internet. It not only protects sensitive data, but also strengthens user trust and thus helps to improve search engine rankings, making it a crucial measure for on-page optimization. The use of SSL certificates is therefore essential for every modern website.

However, the correct implementation and regular maintenance of SSL encryption can present challenges. It is important to be aware of potential issues such as mixed content, SSL connection errors and compatibility with different browsers. Timely renewal of certificates is also crucial to maintain the security and functionality of the website.

In conclusion, investing in strong SSL encryption is a worthwhile measure for any online business or presence on the Internet. It forms the basis for a secure and trustworthy environment for users and customers.