SIGAINT - Definition from the Hotspot Shield Encyclopedia

SIGAINT is a service that offers a secure email service and is operated on the Tor Network as a Tor Hidden Service.

As of 2016 there are around 42,000 users of the SIGAINT service. The service uses SquirrelMail as its main web interface which is an interface that doesn't use JavaScript (JavaScript can be exploited sometimes). Each user has two email accounts. One email account for the Clearnet (standard internet), and another email for use on the Tor network and with .onion domains. As standard, accounts come with 50mb of storage but expire if not used within a year of creation. The SIGAINT service has been widely used and is recommended by many security specialists due to its high level of security.