Tor is not as secure as it is often thought. It needs to be redesigned and/or adopt some modifications from I2P's "garlic routing".

I suggest a complete end-to-end rethink of how anonymous Internet services are done. Instead of it being a tunnel for generic traffic, think of a specialised private protocol for input/output of information. Throw away the highly complex, insecure HTML5 that most hidden services are interacted through. Instead of slow, bloated HTTP requests, think of sockets that stay alive meaning traffic can be high bandwidth and low latency. We could even throw in some modern cryptography like ED25519 which would give some performance benefit. I had an idea for 'heartbeat groups' too which would prevent timing attacks at the ISP/wider Internet level.

If it weren't for the fact that I have a full time job and don't want the Five Eyes on me, I'd build it myself.