University of Bern Research Highlight Missing Consensus in the Ripple Network
Ripple Labs has faced several criticisms in the past. From people doubting the efficiency of its On-Demand Liquidity (ODL) tool to the performance of its XRP token. The firm is often a constant subject of debate. However, a new article is putting the consensus of its very network into question.
Shaky UNL Infrastructure
The Cryptology and Data Security Research Group at the University of Bern published a scathing article pointing out that the Ripple network lacks the critical consensus mechanism.
The research highlights a bit of history for blockchain novices, boiling down to how Ripple managed to strike a balance between Proof-of-Work (PoW) and the Byzantine-Fault-Tolerant (BFT) consensus.
According to the researchers, consensus on a blockchain network relies primarily on two factors – safety and liveness. Safety prevents issues like 51 percent attacks and forks, while liveness ensures that the network continues processing transactions as it should.
Pointing to a separate research paper on the Ripple network, the authors explain that it fails to deliver on both parameters. Particularly, the report faults Ripple’s Unique Nodes List (UNL), which allows every node on the network to declare the other nodes they trust. Ideally, a validator will take messages from nodes on its UNL when validating transactions.
The researchers note that a sufficient number of malicious nodes could send corrupt messages to nodes using the UNL, essentially forcing it to undergo a fork.
The report also explains that Ripple isn’t decentralized. Since the company supplies users with a default UNL and recommends that all validators use it, it appears to be restricting them from making their choices.
Explaining the consequences, the researchers pointed out:
“Our findings show that the Ripple protocol relies heavily on synchronized clocks, timely message delivery, the presence of a fault-free network, and an a-priori agreement on common trusted nodes with the UNL signed by Ripple.”
They added that the network had worked fine for now, but it could also be in grave danger if any of these parameters change.
Node Validators’ Power
While the article hints that Ripple could be denying its validators the decentralization that they deserve, it is worth noting that these people still hold a significant amount of power.
Back in June, validators on the XRPL voted to adopt the Checks Amendment, despite the lack of support from Ripple. The amendment allows users to write checks for a predetermined amount of XRP, which itself can be redeemed at a later date.
Ripple CTO David Schwartz highlighted the power of validators recently. In a tweet, he explained that they could force the company to burn all available XRP tokens if they wished.
Usually, XRP Ledger amendments require 80 percent approval from validators. If they stay above the mark for a fortnight, they are activated. Node validators on the Ripple network have tremendous power, although, as the article highlights, the presence of a few bad apples could make things go south very fast.