Blockchains

• MT Gox Crashed Bitcoin, Trustee Sold the Bottom Blockchain Data Reveals
  • sold off 18k (out of 35k) BTC coinciding with the recent price crash
• AxLang: Formally Verifiable Smart Contracts for the Ethereum Ecosystem
  • no code or technical details released yet

AxLang is based on Scala, and enables secure and full featured smart contract development by supporting both functional programming and formal verification. Its design is driven by the rigorous requirements for solutions serving the world’s largest financial institutions. AxLang is part of Axoni’s blockchain infrastructure, which underpins the broadest reaching and most ambitious permissioned ledger production projects in the world, including $11 trillion of credit derivatives, the world’s leading foreign exchange connectivity network, and various other industry implementations.

• The Emergence of Cryptoeconomic Primitives
  • token curated registries
  • curved bonding
  • prediction markets
  • stablecoins
  • geospatial markets
• Conditional proof of stake hashcash

The idea here is that we set up a smart contract mechanism where along with an email the recipient gets a secret key (the preimage of a hash) that allows them to delete some specified amount (eg. $0.5) of the sender’s money, but only if he wants to; we expect the recipient to not do this for legitimate messages, and so for legitimate senders the cost of the scheme is close to zero

• Prediction markets for content curation DAOs
  • stake money on upvotes/downvotes to flag e.g. scams
  • a DAO makes final moderation decision, voters are rewarded according to outcome
• Settling payments fast and private: efficient decentralized routing for path-based transactions
  • designing better Lightning Networks is now a legitimate field of research ;)

we present SpeedyMurmurs, a routing algorithm for PBT networks that provides formal privacy guarantees in a fully distributed setting and outperforms the state-of-the-art routing algorithms in terms of effectiveness and efficiency

Distributed Systems

• A few things I've learned about computer networking
• Efficient Synchronization of State-based CRDTs

Data consistency often needs to be sacrificed in order to ensure high-availability in large scale distributed systems. Conflict-free Replicated Data Types (CRDTs) relax consistency by enabling query and update operations to be performed locally at any replica without synchronization. Consistency is achieved by background synchronization operations. In state-based CRDTs replicas synchronize by periodically sending their local state to other replicas and merging the received remote states into the local state. This can be extremely costly as the local state grows. Delta-based CRDTs address this problem by defining delta-mutators, which produce small incremental states (deltas) to be used in synchronisation, instead of the full state. However, current synchronization algorithms induce redundant wasteful delta propagation, namely in the general case of a network graph with alternative synchronization paths (desirable to achieve fault-tolerance). In this paper we explore this problem and identify two sources of inefficiency in current synchronisation algorithms for delta-based CRDTs. We evolve the concept of join decomposition of a state-based CRDT and explain how it can be used to boost the efficiency of synchronization algorithms.