## Guest access
1. client send appKey to cnode.
2. cnode forward the request along with the appKey to coim_v1.
3. coim_v1 return the execution result (and a token?)

## Member access
1. client issue a token to cnode.
2. cnode verify the digest. If ok, the random part of the token will be forwared to coim_v1

## coim_v1 returns token
If coim_v1 return a token,