| I am only a dabbler in cryptocurrencies, but let me attempt to compare/contrast this with Bitcoin. Corrections welcome. Bitcoin is peer-to-peer. Anyone can join as a peer at any time. When you want to spend some Bitcoin, you sign a transaction and send it to your peers, who relay the transaction to other peers if the transaction looks valid to them. But the transaction isn't considered "committed" until it becomes part of the blockchain. Peers in the network race to create the next block in the blockchain by proof of work. Whoever creates the next valid block first wins, but for a block to be valid it has to contain a solution to a CPU-intensive problem. The reward for winning the race to create a block is that you get to "mint" some brand new bitcoins to yourself, though the number of new bitcoins in each block is predetermined on a deflationary schedule. Anyone who controls over half of the CPU power can control the blockchain. Hyperledger is not peer-to-peer, it has "nodes" which have to be invited/allowed on the network. Each node has a public/private keypair, and for a transaction to be valid it has to be signed by a node. Nodes only sign transactions if they can achieve consensus with other nodes that the transaction is valid and doesn't double-spend. So you don't have to wait for the next block to get transaction confirmation, you just want to get a node's signature on your transaction The "Practical Byzantine Fault Tolerance" consensus algorithm can continue to function even if up to 1/3 of the nodes are actively trying to subvert it. Apparently bad nodes can be detected and expelled (how?), but if more than 1/3 of nodes suddenly become malicious, double-spending is possible. So you don't want to invite a node unless you trust it. Also, instead of a predetermined schedule for minting new coins, the model is that someone can issue units at any time. This must require a consensus too? Benefits of Hyperledger vs. Bitcoin: Hyperledger can confirm transactions faster since the PBFT algorithm can achieve consensus a lot faster than it takes to build a block (or 2 or 3, to be safe) in Bitcoin. When a transaction is signed by a node, that is a positive confirmation that it was accepted by the network, rather than Bitcoin's less dependable "longest chain wins" rule. Benefits of Bitcoin vs. Hyperledger: Bitcoin, being truly peer-to-peer, does not require the same management of deciding what nodes to trust and allow onto the network, and expelling them when they turn malicious. |
I think it's better, instead, to use bitcoin for some activities and to use a central payment processor for other activities. The central selling points of Hyperledger are "transaction speed" and "low fees"... Why not just use centralized Bitcoin off-chain transactions for these situations, which are even faster and likely even cheaper?
Usually if you want a transaction to be confirmed in under 10 minutes and for a small fee, you're dealing with a transaction under 100 dollars, in which case trusting a central server that is driving off-chain transactions is not a problem.
EDIT: Reflecting more on this, I think a case can be made for a hyperledger-like system beyond a centralized off-chain mechanism, but the problem it solves is small enough that I couldn't imagine using it in the short term. In the long term, something like this may be useful.