Meet NEMid, a secure way to sign in for the modern era. Using secure public key cryptography, NEMid can sign you into compatible websites and apps with only a NEM account through a standalone application. NEMid is similar to the BitID protocol in bitcoin, with the major difference being the type of signature created as well as the format of authentication. A detailed explanation is available on the NEM Blog.
A dummy server is available on GitHub. It gives a fake login experience for you to try out NEMid. This needs to be hosted behind an HTTPS proxy for it to work properly.
In NEMid, the server sends a challenge to the client in a specified format. The client then completes the challenge and sends it to the server (only via HTTPS, this won’t work with HTTP for security) which then logs the user in. This can all be done in two clicks, which much easier and more secure than typing a username and password.