The following article explains the problem of validating a block in a cross-shard transaction in a sharded chain, along with existing solutions.
One of the mentioned solutions is the "Fisherman" idea in which:
"Whenever a block header is communicated between chains for any purpose (such as cross-linking to the beacon chain, or a cross-shard transaction), there’s a period of time during which any honest validator can provide a proof that the block is invalid."
I could not find the seminal paper / article that has proposed the Fisherman idea for the first time.
- Where is the article that has proposed the Fisherman idea for the first time?
Any help is appreciated.