Here are some green VPN services known for their reliability and security:

"GreenVPN" typically refers to a VPN service based on green certificates from the European Union (EU), which provides secure and private internet access. "Vip" often stands for "Value Proposition," indicating that the service offers a premium experience.

1. VPCast - Known for its speed and reliability, VPCast offers a free VPN with features like secure connections, CDN support, and advanced security.

2. StreamEase - Another reliable provider, StreamEase offers a free VPN with similar features to VPCast, including secure connections, DNS protection, and a wide range of video conferencing tools.

3. GreenVPN - This is a well-known green VPN service that offers a free plan with features like encrypted traffic, secure connections, and fast speeds.

4. GreenVPN Free - A simpler version of GreenVPN, offering a free VPN with basic features like encrypted traffic and secure connections.

When choosing a VPN service, it's important to verify their reputation, check customer reviews, and ensure they meet your specific needs, such as the type of internet you're using (Wi-Fi, mobile, etc.). Always prefer a service that offers a good user experience and reliable security.