What type of encryption does the VPN module support?

The VPN module supports AES (Advanced Encryption Standard) encryption because it is widely regarded as a secure and efficient encryption standard used in various security protocols, including VPNs. AES operates on block sizes of 128, 192, and 256 bits, offering strong encryption that is resistant to a range of attacks. This makes it suitable for protecting sensitive data transmitted over the internet in a VPN environment, ensuring confidentiality and integrity.

In contrast, while MD5 is a hashing algorithm, it does not provide encryption but rather checks the integrity of data. SSL encryption typically refers to the overall security protocol that may use various algorithms, including AES, but is not itself an encryption technique. The term "firewall encryption" is not a standard term used in the context of VPNs and does not specify a recognized encryption methodology. Therefore, AES stands out as the correct choice for its direct application in VPN encryption.