Some questions about Lightning and Tor Currently there is a wave of articles claiming the Lightning Network is shrinking. If you look at official statistics, like on p2sh.info, this seems true.

I was told that some of it might be an effect of more and more Lightning nodes using Tor. Imho it is insane to run a LN node at home without Tor, so this might be a good explanation.

But there are some questions left ...


Why do tor nodes don't show up in the statistics? I failed to find a good answer to this.
If tor nodes don't show up in statistics - can non tor nodes route payments over them? Someone mentioned you need bridge nodes for it. Why? And what do bridge nodes do? Are they publicly known, do they have a special setup?


Thanks everybody. Looking forward for your answers.
Generally if you read BOLT 07 you will see that lightning nodes and channels can either be private or public.

This is independent of the fact if they run on tor or not. 

The node announcment message explicitly supports announcing that it runs on tor as written in the BOLT 07


  The following address descriptor types are defined:
  
  
  1: ipv4; data = [4:ipv4_addr][2:port] (length 6)
  2: ipv6; data = [16:ipv6_addr][2:port] (length 18)
  
  
  3: Tor v2 onion service; data = [10:onion_addr][2:port] (length 12)
  
  
  version 2 onion service addresses; Encodes an 80-bit, truncated SHA-1
  hash of a 1024-bit RSA public key for the onion service (a.k.a. Tor
  hidden service).
  
  4: Tor v3 onion service; data = [35:onion_addr][2:port] (length 37)
  
  
  version 3 (prop224)
  onion service addresses; Encodes:
  [32:32_byte_ed25519_pubkey] || [2:checksum] || [1:version], where
  checksum = sha3(".onion checksum" | pubkey || version)[:2].
  
  
  


However I think most users running on tor like their privacy and don't announce their node. 

Generally nodes can only be announced if they have at least one public channel. This is to prevent spam and DoS attacks on the gossip protocol. As some people only have private channels the nodes will not be announced.

Also most mobile nodes like eclair by default open private channels because it might not be so useful for a user that their mobile phone consumes all the data from their carriers data plan to become a routing node.