A proxy server is an intermediary between a device and the internet.
It receives requests, forwards them in its own name and returns the responses.
Definition of a Proxy Server
To the target website, the request appears to come from the proxy rather than from the actual user.
The proxy can filter, cache or modify requests along the way.
Origin of Proxy Servers
Proxies emerged in the early years of the web to save scarce bandwidth through caching and to connect company networks to the internet in a controlled way.
How Does a Proxy Server Work?
The device sends its request to the proxy instead of directly to the website.
The proxy checks it, fetches the response from the target and passes it on.
Types of Proxy Servers
- Forward proxy: acts outwards on behalf of users in a network
- Reverse proxy: sits in front of web servers and distributes requests
- Transparent proxy: works without users configuring anything
- Anonymous proxy: hides the user’s IP address
- Residential and data centre proxies: route through home connections or server addresses
Uses of Proxy Servers
Proxies are used for speed, filtering, load balancing and privacy.
They are also abused to hide the origin of attacks.
Proxy Servers in Cybersecurity
Companies use proxies to filter malicious sites and protect web servers with reverse proxies.
Attackers, on the other hand, use large proxy networks to bypass IP-based blocks.
Against such bots, protection helps that does not only look at the address but, like CDPCaptcha, makes every request cost computational work.
Advantages and Disadvantages of Proxy Servers
Advantages are caching, filtering, central control and more privacy.
Disadvantages are extra hops, possible bottlenecks and the risk that a dubious proxy reads data.
Choosing the Right Proxy Server
Purpose, trustworthiness of the operator, encryption and location are decisive.
Free open proxies should never be used for sensitive data.
Conclusion
Proxy servers are a useful tool for networks and websites.
When defending against bots, however, you have to expect attackers to use them for cover.