CBA announced an Ethereum-based bond market solution[ref]James Eyers (24 Jan 2017), Commonwealth Bank puts government bonds on a blockchain, Australia Financial Review.[/ref]) It’s the usual sort of thing: it’s thought that blockchain and smart contracts will make everything so much easier and cheaper by improving transparency and making the exchange of goods (bond) and value (currency) atomic.
What caught my eye though was the following:
CBA created a digital currency to facilitate the payment for the bond through its blockchain, and Ms Gilder called on the RBA to consider issuing a digital version of the Australian dollar, which she said would provide the market with more confidence.
“For the blockchain to recognise its full potential as an asset register and a payments mechanism, you need a blockchain-friendly form of currency,” she said. “In the future, we would hope the RBA will look at issuing a centrally issued, blockchain-friendly digital currency, which would help because then the currency would be exactly the same as a fiat currency dollar in your account today just in blockchain form.”
James Eyers (24 Jan 2017), Commonwealth Bank puts government bonds on a blockchain, Australian Financial Review
As is all to often with this sort of thing, the proponents of the blockchain solution don’t understand how money works and consequentially don’t realise that statements like “a centrally issued, blockchain-friendly digital currency, which would help because then the currency would be exactly the same as a fiat currency dollar in your account today just in blockchain form” are just wrong.
To provide the atomic operation the article talks about (atomic asset and currency exchange), both asset and currency need to be blockchain native: blockchain needs to the the ‘database of record’ for both. Further, this means that the currency must to be issued on the same blockchain as the asset.
The most obvious solution is a private currency secured against some AUD held by an issuer / market maker. If we want our currency to be exactly the same as AUD then it must be backed by AUD – i.e. a unit of private currency represents a claim on a unit of AUD – otherwise we’re forced to deal with change rates.
The problem is that no-one will want to obtain the AUD required to issue enough private currency to support transactions in the market, so the solution isn’t economically viable. Imagine deploying a market-based solution that requires the market manager to hold the same amount of working capital as the total market valuation? That’s what they’re talking about.
The proposed “centrally issued, blockchain-friendly digital currency” doesn’t solve the problem as the currency wouldn’t live on the same blockchain. All payments would be off-chain via a gateway / oracle and therefore that security-value exchange would not be atomic, with enforcement all of value exchanges off-chain in the gateways / oracles. The nature of the currency doesn’t matter (“blockchain-friendly” is meaningless): for the operation to be atomic the currency and asset must be issued on the same blockchain.
We could support atomic transactions via Ethereum by issuing a currency on-chain (a “cryptocurrency”, as with Bitcoin) and then have an exchange rate between the AUD and on-chain currency. I doubt the bankers would find the currency risk acceptable though. Plus each market participant would need to maintain an account with enough on-chain currency to support their operations, so all we’ve really done is take the “working capital is total market value” requirement and spread it around the market participants, with an additional currency risk. I can’t see the market having a lot of confidence in that solution.
Consequently the blockchain doesn’t buy us much more than a bit of transparency, and there are cheaper and more efficient ways of supporting that without Ethererum. If we dump Ethererum and the cryptocurrency, and build a conventional distributed solution (R3 is default mode without a blockchain – smart contracts optional – should do), then the solution should be quite practical.