How to swap an Ethereum ERC-20 and Neo NEP5 token with a smart contract

Question

I am trying to understand how to swap tokens between blockchains...

let's assume the following:

• I have a smart contract in ETH that issues a token (ABC) as an ERC-20 token

• I have a smart contract in NEO that issues a token (ABC) as an NEP5 token

How can I consolidate them in one blockchain? 

How do ICOs handle multi-concurrency collection?

Thank you for any help anyone can provide!!

Answer 1

Each blockchain is its own separated administration. Therefore it is not possible to swap tokens on-chain as you would need the first chain to rely on stuff that happens on another chain. To do something like this, usually, you need a third party that guarantees that the exchange happens correctly.  Just realise that the management of swapping is an off-chain process in this case. Neo is unique in that it describes a mechanism in which off-chain assets can be exchanged atomically, which is referred to in their whitepaper as "NeoX". Ontology is a collection of protocols of which part is an implementation of the NeoX concept.