Financial Innovation

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On currencies, virtual or otherwise

Posted by Pelle December 7th, 2010 3 comments edit

Currency is one of the most popular buzzwords right now and there are lots of different definitions. I’ll try to unify them in some way and talk about some of the issues involved. Over the next couple of posts I’ll try to analyze what currency is.

Maceration of Money

If you ask most people on the street, currency is what they have in their bank account and in their wallet.

Gamers will tell you that currency can also mean numbers on a screen earned and spent within a game.

Silicon valley hipsters will also try to say that Virtual Currency is the latest monetization strategy out there, often without realizing what it really means.

Community activists also like to remind us of all the successful community currencies that have sprouted up in the past few years.

So my first attempt at a definition is:

A currency is a fungible asset that can be transferred from one person to the other.

Now under that definition we may also need to include stocks, options other securities. As they are generally transferrable and fungible. Most people wouldn’t consider them currency, but they fit the definition perfectly. I’m personally quite happy to consider them currencies.

Virtual Currencies?

What makes a currency virtual or not? It’s not wether it has any real value as World of Warcraft Gold clearly has value. I’d say it depends on the backing of it. So an attempt at a definition:

A virtual currency is a currency backed by the promise of it’s issuer.

Closed loop currencies

A closed loop currency is a currency only meant to be spent with the issuer. Good examples are Starbucks Cards, but most game currencies are also closed loop currencies as you can only use them within the games.

What about Whuffie, Page Rank and other reputation currencies?

That is a good question. These are currencies that are objectively awarded and taken away based on your standing/actions in a community. Pagerank is often also described as a currency. Most of these break my definition above as they aren’t generally speaking transferable.

Whether they are really fungible is also a good question. A Google PageRank of 8 would have to be worth 8 times a PageRank of 1. But clearly that is not the case.

In my next post I explore a few different flavors of what many of us think is just one currency, the all mighty US Dollar.

Open Web Payments - an alternative to OpenTransact

Posted by Pelle July 22nd, 2010 edit

Correction: I had misunderstood this to be an official PayPal proposal. It is actually Praveen and Ray Tanaka private provosal, that they are trying to push with amongst other providers PayPal.

Praveen and Ray Tanaka’s both from PayPal gave a talk at OsCon presenting their new Open Web Payments proposal:

PayPal of course have one of the oldest http based payment APIS out there already, but as PayPal’ers like Praveen have admitted it is pretty old school in its approach and very bloated by now. I’ve been talking quite a lot with Praveen the last half year about OpenTransact , which seems to have had a fair amount of influence on this.

Like OpenTransact Open Web Payments utilizes OAuth as well as WebFinger. Where it differs is it’s use of Atom and AtomPub and more fundamentally that it ignores URI’s as a fundamental part of the protocol.

Atom transactions

I think Atom in itself could be a good way of publishing transaction data, but it shouldn’t be the only way. There also needs to be json and microformats. XML and in particular heavily namespaced XML is not very popular today with developers outside the enterprise. The datamodel isn’t too bad but I think it is too complex. There are too many data elements:

AtomPub for payments

To create a payment you POST a chunk of atom xml to a URL creating an entry. I’m glad it follows HTTP conventions. I’m not in love with allowing GETS for modifying transactions. And a refund might be better modeled with a DELETE

This is an example of a transaction:

Contrast this with OpenTransacts equivalent:

POST /transactions/usd HTTP/1.1
Authorization: OAuth ... oauth_token="ad180jjd733klru7", ...
Content-length: 239

amount=25.00&to=[email protected]&memo=Milk

Again too much information. We already know the sender through the OAuth token, no need to repeat it. Why do we need enter this much information about about the recipients. A single URI, email address or other identifier should be sufficient, particular as we are using webfinger.

What this does have that OpenTransact doesn’t support at the moment is multiple recipients. We could add that using the following convention:

POST /transactions/usd HTTP/1.1
Authorization: OAuth ... oauth_token="ad180jjd733klru7", ...
Content-length: 239

amount=25.00&to=[email protected]&memo=Milk&amount.2=2.00&to.2=[email protected]

Where art thou URI

Each transaction does have a URI which is excellent. Posting to an atom resource should create a URI. The rest of the API misses an opportunity to look at the fundamental concept of value as a resource.

For historical reasons payment apis have traditionally followed the messaging model. This goes back to the days before financial institutions were online (see my previous article on the sorry state of payment standards). PayPal, VISA, M/C, SWIFT are financial intermediaries sending messages with instructions back and forth. This message oriented way of thinking about payments is what causes much of the complexity as you need to include lots of redundant information in the payment message.

The web on the other hand works using the concept of resources and actions. It is pretty object oriented in this way. Messaging applications can be created on top of the web, but the complexities are hidden behind this object oriented world. This is how atom, twitter, facebook etc all work.

The best example of a field all payment messaging standards require is the currency field. On the web we don’t need this as we have URI’s.

A payment is the transfer of one resource to another. So lets model that in the restful object oriented way. Each currency has a separate URI:


HTTP POST to this URI to transfer funds. HTTP GET to get transactions in that currency.

In addition in the above grocery transaction the funding types elements. Neither the merchant nor the consumer cares about these. They are also extremely specific to PayPal and are likely not of any interest to most other people wanting to implement this, such as banks. They could be modeled into the URIS as well:

  • – do whatever default behavior is

These options could be presented to merchant using WebFinger.

This concept of using URI’s to represent value is key to OpenTransact’s simplicity.


I am glad that Praveen is at PayPal trying to open up their payment world. We can’t discount the importance of an evangelist within PayPal pushing for open standards. I just don’t think it is radical enough. I also think it is too complex both for consuming developers and for developers creating new financial services supporting it.

Any good developer could definitely work with it, but for the majority of developers creating simple PHP/ASP type sites it would present some major hurdles the same way OAuth 1 has. OAuth 2 learnt from this and PayPal’s proprietary API’s have always been targeted at these kinds of developers. While conceptually it is simpler than the old API’s, I think many developers would find it easier to deal with the old API in practice due to the complexities of XML.

Another important question is if PayPal are actually committing to this. I believe PayPal has good intentions with this, but other large corporations were notorious for bringing down competitors with nothing but press releases announcing new products.

It is more of a full stack though than OpenTransact. Hopefully we can work together on the lists to create a common full stack. I see this as Ray and Praveen’s reply to OpenTransact and as the start of a conversation. Similar to OAuth Wrap being the response to the complexity of OAuth1 which lead to the great new OAuth2 standard.

How OAuth beat Chip and Pin

Posted by Pelle February 12th, 2010 1 comments edit

2 news stories on the same day are quite interesting in their contrast.

Pin and Chip is broken

The first one has the collective might and minds of the European banking system and their suppliers who overlooked a slight issue in their authentication protocol for authenticating Chip cards with a pin number. In Europe most Visa/MC cards are smart cards and have to be authenticated with a pin. This in theory allows for an authenticated payment message.

Only problem was that, well one very important bit of the message was not authenticated leaving a gaping hole. I won’t go into the details as well as Ross Anderson does. He is one of the security researchers who discovered the flaw. Unfortunately it sounds like carders discovered it before them.

Now what to do with these supposedly safe authenticated transactions? There is no way of knowing which ones were fake. You can’t mass revoke all european cards. Some one is in a bit of a bind right now.

Grader’s security screw up

The second story was about HubSpot a Cambridge, Mass. based startup who self admittedly screwed up and let a malicious user comprise the security of their Grader service a rating service for twitter users.

Granted we are not talking about a system that handles the majority of Europe’s electronic point of sales transactions here. But they know they screwed up. However due to the fact that Grader used OAuth they were able to mitigate any damage pretty quickly by asking Twitter to revoke their Consumer credentials and any tokens they had issued to it.


The difference is that while both Chip and Pin and OAuth are ways of doing delegated authentication, the only token to revoke in the Chip and Pin scheme is in the card itself. The standards behind Chip and Pin assumes that it’s technology is perfect and through their rule books that all parties involved along the long chain from the card to the issuing bank can automatically be trusted.

This is basically the exact issue I described in The sorry state of Payment Standards.

OAuth does not define how a user authenticates himself to either of the services involved, rather it is focused on the delegation.

The delegation is done in the form of an authorized token that can be equipped with limits and can at any time be revoked. It is under the control of the user. In this case Grader themselves request the revocation as they knew that all of their credentials were compromised. Where do the European bankers even start to clean up this mess?

I think OAuth a simple (as authentication standards go) standard developed on a mailing list by a small group of developers has incredible potential in payments applications. This is of course why we picked it as one of the fundamental building blocks for OpenTransact.

Is OAuth perfect? Probably not. Nothing is 100% secure. It has had one serious security flaw which was fixed. But by design it is revokable. You can do something about it if something goes wrong. There is now an IETF OAuth Working Group working on making it an official internet standard.

OpenTransact a tiny payment standard

Posted by Pelle February 11th, 2010 1 comments edit

As I mentioned in my last post The Sorry state of Payment Standards I wanted to blog about OpenTransact which so far is probably one of the most important outcomes of the Agile Banking mailing list set up after my talk last year on Agile Banking.

OpenTransact was designed to be very simple and is based on REST the best practice for current web API design. It should be so easy to implement for developers that there really shouldn’t be an excuse not to implement it.

An OAuth authenticated HTTP POST request to assets URL containing the parameters amount, to and optional memo field. Payer is deduced from the OAuth token.


POST /transactions/usd HTTP/1.1
Authorization: OAuth ... oauth_token="ad180jjd733klru7", ...
Content-length: 239

amount=10.00&to=[email protected]&memo=Milk

The above example shows a payment of $10 to [email protected] from the user who authorized the “ad180jjd733klru7” OAuth token.

Using the Ruby OAuth gem you would write the above as: "/transactions/usd", :amount=>10, :to=>"[email protected], :memo=>"Milk"

That is pretty much it. But please do read on for more about motivations, issues and applications.

The sorry state of payment standards

Posted by Pelle February 4th, 2010 edit

Since my talk last year at Reboot on Agile Banking the Agile Banking Mailing List has been quite active with lots of different ideas. One of the most important yet also simple products of the list has been OpenTransact which I now realize I haven’t even mentioned on my blog.

OpenTransact aims to be the worlds simplest technical standard for transferring some sort of value between 2 accounts. We wanted it to be so simple that there wouldn’t be a good technical excuse for not implementing it and also make it extremely simple to build all sorts of new value added services on top of it. You can find out more at the OpenTransact site and I will post a detailed article about it tomorrow.

In this article I will focus on what we’ve got. Current payment standards and bank business processes are incredibly complex and I don’t pretend to understand all of it, but I will try to present a much simplified version of what goes on.

What is wrong with existing Payment Standards?

Complex messages

The big issue with most of them is that they are ancient (SWIFT the standard banks use to transfer funds internationally dates back to the mid 70s). Most of them are designed for ancient technology like mainframes with batch processing as well as ancient business practices such as delayed settlement and bank opening hours.

Most of these standards are message based and extremely complex.

SWIFT has 25 standard data elements and 79 types of messages with strange names like MT542. People make good money specializing in specific message types. You often see programmer jobs in the financial industry calling for 3 years of experience in eg. MT530.

ISO 8583 which is used for handling most payment card transactions dates from 1987 is a little better in that at least it does expect to be able to send one or two small messages online, but still most of the heavy lifting is done after the fact in the settlement phase.

Most countries have their own electronic banking clearing systems with their own set of standards and procedures. The largest US clearing system ACH won’t even let you at their online rules website without buying a $79 book.

Security nightmares

Any non cash financial transaction consists of one or more entries known as book entries into various companies databases. By definition any act of creating a financial transaction is delegated by you to someone else. Whenever your transaction involves another bank your original delegation gets delegated onwards to x number of other institutions. Unfortunately the transactions are often unauthenticated. Whether you are sitting in a bank office ordering a wire transfer or handing a waiter your credit card you are delegating authority to transfer funds out of your account. This is why a check says “Pay to the order of…”.

Card payments do support some level authentication from pin to signing via an onboard smart card. But they aren’t used when performing an internet payment. This is obviously where much of the fraud goes on. Credit Card or ACH fraud essentially boils down to convincing (delegating) someone to transfer funds from the victims account.

Since you can’t satisfactorily secure the payment message most of these standards come with complex reconciliation standards that make up most of their complexity and even larger and more complex rule books. These rules are what allow you to deny a transaction when you get your statement a month later after the fact.

Enter PayPal

PayPal’s original Website Payment API while not a standard was a big step up over the actual standards in that it was born of the web. Web 1.0 yes but still the web. So rather than using REST to hide some of the complexity it uses a single URL with lots of different fields including optional non payment fields such as address and shipping details.

A big issue that PayPal had was that they still had to interface with the traditional banking world with their settlement times and insecure payments. To make it economical for them they need to use ACH and similar slow low cost national payment networks guaranteed by credit cards if these don’t go through. This is where much of the complexity of dealing with their Instant Payment Notification comes from.

Most of PayPal’s competitors use similar API’s to PayPal’s, but there hasn’t been any real standardization on it yet.

Their new Adaptive Payment API is much clearer. Yet still fairly complex for a new developer faced with it. And no it’s still not REST.

Why is it like this?

Closing Time

There are many reasons why banking related standards are complex. Most of them are historical. For example banks still operate 5 days a week with close of business at some time like 6pm decided many decades ago by gentlemen in top hats. Of course they do work 24 hours but all their processes are still based on this pre online world.

This means there is still a lot of batch processing going on in that last hour before closing. Most banks have a cutoff time a couple hours earlier than their official closing time to give them time to batch up and reconcile the days business. This is why you have to rush to the bank with your checks before 3pm on a Friday or it won’t get credited until Monday evening.


Settlement is another important issue that all of these ancient standards have to deal with. Once you’ve bought that dry martini in the bar after work with your debit card, the money doesn’t actually leave your account yet. Your bank basically puts a hold on your money first. Then over the next couple of days they settle it through a network of banks and institutions depending on the country. Most of the settlement processes is done through batch processes once a day, the more step between your bank and the bars bank the longer settlement takes.

Most of these settlement (clearing) times are standardized by rules set out by central banks or banking associations. The holy grail for many of these systems is to reach what is known a T+0 clearing, which is fancy banker speak for instant clearing. It will take a long time for this to happen in most large economies like the US as there isn’t really a demand for it from anyone except consumers and small businesses.


Any new standard or API that attempts to deal with the existing banking standard is very difficult to simplify. You need to account for each countries settlement and fraud prevention rules. SWIFT was updated to a fancy smancy new XML standard, which didn’t do anything to simplify it besides making it easier to parse.

Any kind of innovation in this needs to be designed for an online world with 7 days, 24 hours and clear simple standards that only aim to solve a simple need. We have had this magic new technology now called HTTP thats been here for close to 20 years now and it’s been kind of successful. OpenTransact is only a very thin layer on top of HTTP and uses OAuth for its authentication, I think it is going to be big. But I will write more on that in my next post.