Chinese netizens finding it increasingly difficult to bypass the Great Firewall after a recent crackdown on virtual private network (VPN) services have found an unlikely ally in a new public relay VPN service from Japan.

The VPN Gate Academic Experiment Project (h/t TechInAsia) was set up by researchers at the Graduate School of Japan’s University of Tsukuba with a mission to "expand the knowledge of ‘Global Distributed Public VPN Relay Servers’."

The free service requires no user registrations and bills itself as having "strong resistance against firewalls" because its VPN servers are provided by volunteers around the world and therefore hosted by different ISPs and in different physical locations.

VPN Gate explains more in patchy English below:

The number of volunteers increases or decreases every day, and each IP address vary every time. If something "out-of-order" will occur on the government's firewall, whole the VPN Gate Relay Server are not affected. If a few VPN servers become unreachable from your country, you can still reach other VPN servers.

The platform supports the SSL-VPN (SoftEther VPN) protocol, L2TP/IPsec, OpenVPN, and Microsoft SSTP protocol.

This amount of choice is useful because the Chinese government recently began shutting down foreign-owned VPN services, rendering OpenVPN virtually useless inside the Great Firewall, as explained by VPN Instructions.

It’s no surprise then to see that of the 4,800 sessions established within the past three hours (at time of writing), the overwhelming majority are from users inside China

At present there are 87 public VPN servers worldwide offered by the platform, with the Japanese researchers having also taken measures to enable access to the VPN server list in the event that the VPN Gate web site is blocked.

Here's how the site says users can get around blocks:

If you are a citizen of the country which has a government's firewall with unknown error which prevents accesses to the www.vpngate.net from the domestic Internet, please access to the Mirror Sites List page, copy the URL list and paste it to SNS, Blogs or community forums in your country to help VPN users in your country.

China is of course not the only country where tighter regulation of the internet is further squeezing online freedoms and making things difficult for business users.

It recently emerged that Iran has blocked most VPNs in a bid to prevent users from visiting certain banned web sites as the Islamic republic gears up for elections in a few months’ time.