WebRTC is all about security and encryption. These are not an afterthought. They're intimately interwoven at the design level and are mandatory. For example, you cannot stream audio or video clearly (without encryption) via WebRTC.
To start with this recipe, you need certificates. These are the same kind of certificates used by web servers for SSL-HTTPS.
Yes, you can be your own Certification Authority and self-sign your own certificate. However, this will add considerable hassles; browsers will not recognize the certificate, and you will have to manually instruct them to make a security exception and accept it, or import your own Certification Authority chain to the browser. Also, in some mobile browsers, it is not possible to import self-signed Certification Authorities at all.
The bottom line is that you can buy an SSL certificate for less than $10, and in 5 minutes. (No signatures, papers, faxes, telephone calls… nothing is required. Only a...