Stellar (XLM) Network Downtime Shows Weakness in Validators System
The Stellar network uses validators with a known reputation, leading to a breakdown of consensus.
The Stellar (XLM) network was down for about two hours on Wednesday, due to a crash in trusted nodes, Reddit users noted. The Stellar network uses a series of nodes run by voluntary power users, as well as by the Stellar Development Foundation. The Stellar network is now back to full functioning.
The problem seems to be in the voting system, which assigns reputation to nodes. For some reason, voters boosted the reputation of SDK nodes, which were mostly responsible for the consensus. This also meant that a system designed to be distributed ended up centralizing itself due to voting behavior.
The flaws in SDK nodes meant not enough validators were available to achieve consensus and a permanent record of transactions. This showed a significant weakness in the Stellar network, as a single entity was in fact responsible for consensus.
In the past, the rather obscure system of nodes and votes on the Stellar network has received criticism for potentially allowing centralization, but the network breakdown shows the reality of the situation. The event is especially serious, given Stellar’s claims that its technology is robust enough to carry international banking transactions.
The news so far failed to bring down the XLM market price, which is on a spree, rising more than 23% overnight to $0.14. But XLM is yet to prove its value as a platform for business applications. XLM is viewed as the open source version of Ripple’s system of servers, in essence also attempting to become an asset for business use. Stellar has partnered with IBM to explore the possibilities for international remittances based on its consensus protocol.
To compare, Bitcoin consensus is achieved by communication through thousands of voluntary nodes. Other networks rely on a smaller number of validators, ranging between 101 for Lisk (LSK), 21 for EOS, 26 for TRON (TRX). Projects like Binance Chain rely on a relatively small number of validators controlled by the exchange. This means that a crash of a sufficient number of nodes means the distributed ledger cannot be reliably verified and may be open to attacks.