As mentioned a couple weeks ago I have published a new research paper entitled: “Watermarked tokens and pseudonymity on public blockchains”
In a nutshell: despite recent efforts to modify public blockchains such as Bitcoin to secure off-chain registered assets via colored coins and metacoins, due how they are designed, public blockchains are unable to provide secure legal settlement finality of off-chain assets for regulated institutions trading in global financial markets.
The initial idea behind this topic started about 18 months ago with conversations from Robert Sams, Jonathan Levin and several others that culminated into an article.
The issue surrounding top-heaviness (as described in the original article) is of particular importance today as watermarked token platforms — if widely adopted — may create new systemic risks due to a distortion of block reorg / double-spending incentives. And because of how increasingly popular watermarked projects have recently become it seemed useful to revisit the topic in depth.
What is the takeaway for organizations looking to use watermarked tokens?
The security specifications and transaction validation process on networks such as the Bitcoin blockchain, via proof-of-work, were devised to protect unknown and untrusted participants that trade and interact in a specific environment.
Banks and other institutions trading financial products do so with known and trusted entities and operate within the existing settlement framework of global financial markets, with highly complex and rigorous regulations and obligations. This environment has different security assumptions, goals and tradeoffs that are in some cases opposite to the designs assumptions of public blockchains.
Due to their probabilistic nature, platforms built on top of public blockchains cannot provide definitive settlement finality of off-chain assets. By design they are not able to control products other than the endogenous cryptocurrencies they were designed to support. There may be other types of solutions, such as newer shared ledger technology that could provide legal settlement finality, but that is a topic for another paper.
This is a very important issue that has been seemingly glossed over despite millions of VC funding into companies attempting to (re)leverage public blockchains. Hopefully this paper will help spur additional research into the security of watermarking-related initiatives.
I would like to thank Christian Decker, at ETH Zurich, for providing helpful feedback — I believe he is the only academic to actually mention that there may be challenges related to colored coins in a peer-reviewed paper. I would like to thank Ernie Teo, at SKBI, for creating the game theory model related to the hold-up problem. I would like to thank Arthur Breitman and his wife Kathleen for providing clarity to this topic. Many thanks to Ayoub Naciri, Antony Lewis, Vitalik Buterin, Mike Hearn, Ian Grigg and Dave Hudson for also taking the time to discuss some of the top-heavy challenges that watermarking creates. Thanks to the attorneys that looked over portions of the paper including (but not limited to) Jacob Farber, Ryan Straus, Amor Sexton and Peter Jensen-Haxel; as well as additional legal advice from Juan Llanos and Jared Marx. Lastly, many thanks for the team at R3 including Jo Lang, Todd McDonald, Raja Ramachandran and Richard Brown for providing constructive feedback.