Are Bitcoin Block Hashes Predictable?

What are the major differences between block chain based digital currencies like Bitcoin and issuer server based Ricardo?

• Here's a url to the Ricardo wiki http://wiki.dgcmagazine.com/index.php?title=Ricardo I'm curious if the emergence of Bitcoin and similar type crypto currencies automatically trumps issuer based models like Ricardo. Is there room for both to coexist and complement each other? Why doesn't Ricardo get its due share of mentions for foreseeing the need for new payments systems over the internet?

• Answer:

  From what I can gather, this system works on a three-party trusted system, similar to an escrow system.  In my opinion (disclaimer below), this system still has counterparty risks because the third system (trusted entity) can still be co-opted by either party, or yet another entity who may have interest in the transaction.  Some examples that uses 3rd party systems are like SSL, where you trust an intermediary to secure the transaction. Bitcoin is a "trustless" system - meaning, the network as a whole, which is comprised of all the miners and peering nodes, process the transaction that requires none of the infrastructure to be setup for two people on the network to conduct transactions.  Unless the entire network is compromised, then Bitcoin (the network) seems to be a superior solution. General Disclaimer: I'm a co-founder of a Bitcoin startup, http://expco.in/r6, so my views and opinions are going to be biased accordingly.