Some argue that purchasing certificates for securing websites by SSL and securing software by code signing is a costly venture for small businesses. However, the emergence of free alternatives, such as Let's Encrypt, has changed this. HTTP/2, the latest version of HTTP protocol, allows unsecured connections in theory; in practice, major browser companies have made it clear that they would support this protocol only over a PKI secured TLS connection. Web browser implementation of HTTP/2 including Chrome, Firefox, Opera, and Edge supports HTTP/2 only over TLS by using ALPN extension of TLS protocol. This would mean that, to get the speed benefits of HTTP/2, website owners would be forced to purchase SSL certificates controlled by corporations.