Presumably you&#x27;re not putting the actual messages in the blockchain. You can use it for metadata like encrypted messages or keys, and use it as a trusted clock for TTLs.<p>The more confusing requirement is that they want instant communications over a blockchain.<p>But at a higher level, this is a sort of odd set of requirements. &quot;You have to use a blockchain somehow&quot; is a class project requirement, not an actual project deliverable; nobody should care if it actually uses a blockchain and how as long as it satisfies the required security goals, right? It almost sounds like this RFP was written to describe one person&#x27;s&#x2F;group&#x27;s existing product.