Privacy is one of the essential pillars for the widespread adoption of blockchains, but public blockchains are transparent by nature. Modern analytics techniques can easily subdue the pseudonymity feature of a blockchain user. Some applications have been able to provide practical privacy protections using privacy-preserving cryptography techniques. However, malicious actors have abused them illicitly, discouraging honest actors from using privacy-preserving applications as mixing user interactions and funds with anonymous bad actors, causing compliance and regulatory concerns. In this paper, we propose a framework that balances privacy-preserving features by establishing a regulatory and compliant framework called Selective De-Anonymization (SeDe). The adoption of this framework allows privacy-preserving applications on blockchains to de-anonymize illicit transactions by recursive traversal of subgraphs of linked transactions. Our technique achieves this without leaving de-anonymization decisions or control in the hands of a single entity but distributing it among multiple entities while holding them accountable for their respective actions. To instantiate, our framework uses threshold encryption schemes and Zero-Knowledge Proofs (ZKPs).
We propose a middleware solution designed to facilitate seamless integration of privacy using zero-knowledge proofs within various multi-chain protocols, encompassing domains such as DeFi, gaming, social networks, DAOs, e-commerce, and the metaverse. Our design achieves two divergent goals. zkFi aims to preserve consumer privacy while achieving regulation compliance through zero-knowledge proofs. These ends are simultaneously achievable. zkFi protocol is designed to function as a plug-and-play solution, offering developers the flexibility to handle transactional assets while abstracting away the complexities associated with zero-knowledge proofs. Notably, specific expertise in zero-knowledge proofs (ZKP) is optional, attributed to zkFi's modular approach and software development kit (SDK) availability. .
Executing on decentralized exchanges (DEXs) provides a higher level of security for clients’ funds. Clients can execute their trades directly from their own wallet, using smart contracts, and keep custody of their assets. This higher level of security comes at the cost of “gas fees”, which users of a blockchain have to pay to validators for verifying transactions. In this paper, we analyze the effect of gas fees and network speed on execution cost and liquidity distribution on the largest DEX, Uniswap v3. Specifically, we use the entry of Polygon, a scaling solution to the incumbent Ethereum, as an exogenous shock to gas fees reduction and speed increase. We expect that lower gas fees and higher speed on Polygon should lead to higher concentration of liquidity around the market price. Indeed, it becomes easier for liquidity providers to revise their positions and re-post liquidity around the market price. Our preliminary findings show that, whereas overall market depth on Polygon is lower compared to Ethereum, liquidity is indeed more concentrated around the market price. This higher liquidity concentration is especially important for execution of smaller trades. Indeed, we find that price impact for smaller trades (up to $10K) is lower on Polygon, compared to Ethereum.
On November 22nd 2022, the lending platform AAVE v2 (on Ethereum) incurred bad debt resulting from a major liquidation event involving a single user who had borrowed close to $40M of CRV tokens using USDC as collateral. This incident has prompted the Aave community to consider changes to its liquidation threshold, and limitations on the number of illiquid coins that can be borrowed on the platform. In this paper, we argue that the bad debt incurred by AAVE was not due to excess volatility in CRV/USDC price activity on that day, but rather a fundamental flaw in the liquidation logic which triggered a toxic liquidation spiral on the platform. We note that this flaw, which is shared by a number of major DeFi lending markets, can be easily overcome with simple changes to the incentives driving liquidations. We claim that halting all liquidations once a user's loan-to-value (LTV) ratio surpasses a certain threshold value can prevent future toxic liquidation spirals and offer substantial improvement in the bad debt that a lending market can expect to incur. Furthermore, we strongly argue that protocols should enact dynamic liquidation incentives and closing factor policies moving forward for optimal management of protocol risk.
Using the devaluation of the TerraUSD peg as a case study, this column shows how algorithmic stablecoins are vulnerable to speculative attacks when the system is under-collateralised. The authors point to solutions – stable collateral and over-collateralisation – to stabilise the peg.
We assess the market risk of the lending protocol using a multi-asset agent-based model to simulate ensembles of users subject to price-driven liquidation risk. Our multi-asset methodology shows that the protocol’s systemic risk is small under stress and that enough collateral is always present to underwrite active loans.
The paper study the mechanisms that govern price stability of MakerDAO's DAI token, the first decentralized stable coin.Using data on the universe of collateralized debt positions, we show that DAI price covaries negatively with returns to risky collateral. The peg-price volatility is related to collateral risk, while the stability rate has little ability to stabilize the coin. The introduction of safe collateral types has led to an increase in peg stability
I combine data from Airbnb and Zoopla and examine how the prices of individual houses evolve over time as Airbnb penetrates the market in Greater London.