What is Shadowsocks and How Does It Work?

Alina M

Author

Today, many users face with all kind of restrictions while spending time on the Internet or working there. There are also concerns rising, regarding worsening scenarios of Internet censorship and privacy. With all that, users are more and more intrested in finding ways to continue workng on the Internet while bypassing geo-restrictions and securing their privacy. Fortunatly, there are plenty of VPNs and proxies that might help. In this article we’ll explore Shadowsocks proxy protocol, how it works and why you might prefer it to VPN.

What Is Shadowsocks?

Shadowsocks is an encrypted proxy protocol. Originaly, it was created in 2012 by the Chinese developer Clowwindy to skirt China’s infamous “Great Firewall,” but it quickly spread globally as it proved to be the most effective server to evade censorship while keeping its design lightweight and efficient.

Shadowsocks is not the same thing as VPN. Instead, it’s a SOCKS5 proxy with embedded encryption, proving to be considerably effective for users whose requirement is just to circumvent blocks without sending all their Internet traffic through the same tunnel.

This is what enables Shadowsocks to offer selective routing of traffic whereby users can select which apps or websites go through the encrypted proxy while others connect directly to the Internet. This feature is very helpful in areas where certain services are blocked and yet access to local websites should still be direct.

How does Shadowsocks work?

At very core, Shadowsocks acts as a secure intermediary between your device and the internet. When you connect to any web address or online service, it normally goes through your internet service provider, who can easily monitor or block access to certain sites. Shadowsocks interrupts this process by encrypting your traffic and sending it via a remote server, effectively masking your activity from prying eyes.

Shadowsocks makes use of Authenticated Encryption with Associated Data (AEAD) ciphers, like ChaCha20-Poly1305 and AES-256-GCM, that ensure that your data remains confidential and tamper-proof. These encryption algorithms are considered widely secure and form the core of other privacy tools, including WireGuard and Signal. However, encryption is sometimes not sufficient to bypass censorship engines in countries like China.

To this end, Shadowsocks provides obfuscation plugins, including simple-obfs and Cloak, which camouflage encrypted traffic as regular HTTPS traffic. This makes detection and blocking use of proxy a real challenge for ISPs or any government firewalls.

Some Advantages

One of the strongest points of Shadowsocks is its flexible traffic routing. There are mainly three modes:

• Direct Mode: In this mode, no traffic is proxied. That is very useful in applications or websites not requiring encryption nor bypassing restrictions.
• PAC Mode: In this mode, it intelligently routes the traffic based on predefined rules. For example, you can configure it to only proxy requests to blocked websites while it connects directly to local services.
• Global Mode: All internet traffic is routed through the Shadowsocks server, similar to how a VPN operates. It is the best option for those users who want protection all over and may experience slightly reduced speeds due to the encryption overhead.

Shadowsocks has been normally praised for having low latency and incurring only a small loss in speed, around 3-5%. This is due to the fact that it works at the application layer-so-called SOCKS5-compared to some VPNs, which tunnel all traffic at the network layer.

Shadowsocks vs. VPN: Which Is Right for You?

While both Shadowsocks and VPN are for bypassing censorship and securing the internet, they differ quite a lot in their approach and use cases. Understanding the differences will be helpful in determining which tool best suits your needs.

When to Choose Shadowsocks over a VPN

Shadowsocks excels in situations that require selective encryption and speed. For instance:

• Accessing banned websites in countries that have a very high level of censorship, like China or Iran.
• Streaming or gaming, where the lowest latency is crucial.
• By using specific applications that require encryption while allowing others to connect directly.

A VPN is usually better when you:

• Full-device encryption for everything online.
• Access geo-restricted content from several countries.
• Ease of use, because most VPNs support one-click setup, with user-friendly apps.

Potential Vulnerabilities

There are several issues users might face while using Shadowsocks:

Lack of Official Audit: Unlike the case of OpenVPN, which has been subjected to extensive security audits, Shadowsocks has never gone through formal scrutiny by third-party organizations. While in theory any community is free to take up the code to review, as in the case with all open-source projects, the absence of an official audit may raise concerns for some users.

Advanced Firewalls Detection: Advanced censorships, such as China’s Great Firewall, have worked out ways of detecting and blocking proxy traffic even with obfuscation. The techniques of deep packet inspection and active probing make this possible.

No Built-In Anonymity: It lacks the anonymity of tools like Tor or no-logs VPNs. If anonymity is your main priority, you may find yourself having to add additional privacy tools on top of Shadowsocks.

How to Improve Shadowsocks Security

Below are steps you can try to further your safety while using Shadowsocks:

• Obfuscation plugins like simple-obfs or Cloak: helping to disguise your traffic and thus not give you away as easily.
• Hosting over a Trusted VPS: Ensure that you never utilize free or low-quality proxy services, for they will either record every bit and piece of your activities or share them.
• Combine with Tor: This will route Shadowsocks’ traffic further to the Tor network for even greater anonymity.

Frequently Asked Questions