Revert "Update mixo.py"

This reverts commit 26a56d3cb58c5e88b833c2b10118697431b4b944.
Revert "different key for each connection."

This reverts commit 5e2cc80e0a00f5d5344dd12597128f26fbc8474a.
Revert "different key for each connection."

This reverts commit 4f27322613e584df32a21fb064ec2c0a378a2a32.