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A New Digital Wallet for a New Digital Currency

FacebookCoin is being announced on Tuesday! It's called Libra, and Facebook are apparently stressing very hard that everyone should call it Libra, and not Facebook-anything. And definitely not ZuckerBucks...

Libra's byzantine tolerance on a permissioned network is an incoherent design; Libra has no transaction privacy; Libra HotStuff BFT is not capable of achieving the throughput necessary for a payment rail; Libra's Move language is not sound; Libra's cryptography engineering is unsound; Libra has no capacity for consumer protection mechanisms. Answer:

The [Libra] coin is really a Facebook project. It is not live yet, giving governments the opportunity to kill this project before it gets off the ground and gives rise to cybercriminals who couldn't capitalize on existing cryptocurrencies. In particular, the [Internal Revenue Service] IRS and [the U.S. Treasury's Financial Crimes and Enforcement Network] FinCEN should take action now...

Roughly a dozen fake accounts, pages and groups scattered across Facebook and its photo-sharing app Instagram present themselves as official hubs for the digital currency, in some cases offering to sell Libra at a discount if viewers visit potentially fraudulent, third-party websites...

a Libra go client library with crypto verifications

a Java library for interacting with the Libra blockchain.

a leader-based Byzantine fault-tolerant replication protocol for the partially synchronous model. Once network communication becomes synchronous, HotStuff enables a correct leader to drive the protocol to consensus at the pace of actual (vs. maximum) network delay - a property called responsiveness - and with communication complexity that is linear in the number of replicas. To our knowledge, HotStuff is the first partially synchronous BFT replication protocol exhibiting these combined properties. Its simplicity enables it to be further pipelined and simplified into a practical, concise protocol for building large-scale replication services.

Most protocols contain quadratic voting steps. When Byzantine consensus protocols were originally conceived, a typical target system size was n=4 or n=7, tolerating one or two faults. But scaling Byzantine Fault Tolerance (BFT) consensus to n=2000 means that even on a good day, when communication is timely and a handful of failures occurs, quadratic steps require 4,000,000 messages. A cascade of failures might bring the communication complexity to whopping 8,000,000,000 (!) transmissions for a single consensus decision...