In a recent work by Augot et al. (2017), a scheme is proposed to build an identity system on top of the Bitcoin network. However, this proposal incurs very high costs since Bitcoin transactions require heavy fees. The current work introduces modifications to their scheme to make it more cost...
We propose a model which uses the exchange rate of Bitcoin against the US dollar to predict the computing power of Bitcoin network. We show that free entry places an upper-bound on mining revenues and we devise a structural framework to measure its value. Calibrating the model’s parameters allows us...
We analyze a two-country economy with complete markets, featuring two national currencies as well as a global (crypto)currency. If the global currency is used in both countries, the national nominal interest rates must be equal and the exchange rate between the national currencies is a risk-adjusted martingale. We call the...
In a novel model of an endowment economy, we analyze coexistence and competition between traditional fiat money (Dollar) and another intrinsically worthless medium of exchange, not controlled by a central bank, such as Bitcoin. Agents can trade consumption goods in either currency or hold on to currency for speculative purposes....
The introduction of a central bank digital currency (CBDC) allows the central bank to engage in large-scale intermediation by competing with private financial intermediaries for deposits. Yet, since a central bank is not an investment expert, it cannot invest in long-term projects itself, but relies on investment banks to do...
Committee-based blockchains are among the most popular alternatives of proof-of-work based blockchains, such as Bitcoin. They provide strong consistency (no fork) under classical assumptions, and avoid using energy-consuming mechanisms to add new blocks in the blockchain. For each block, these blockchains use a committee that executes Byzantine-fault tolerant distributed consensus...
We analyze from the game theory point of view Byzantine Fault Tolerant blockchains when processes exhibit rational or Byzantine behavior. Our work is the first to model the Byzantine- consensus based blockchains as a committee coordination game. Our first contribution is to offer a game-theoretical methodology to analyse equilibrium interactions...
We show that the single-server computational PIR protocol proposed by Holzbaur, Hol- lanti and Wachter-Zeh in [HHW20] is not private, in the sense that the server can recover in polynomial time the index of the desired file with very high probability. The attack relies on the following observation. Removing rows...