Earlier this week, Stellar Network faced an accidental fork that occurred after the failure of their underlying consensus system.
The event was first reported by Joyce Kim, the Executive Director at Stellar Development Foundation. She tried outlining the reasons behind the failure of their deterministic consensus system, blaming its limitations as one of the major reasons that explains why their network got forked at first place. She wrote:
“A deterministic asynchronous consensus system can have at most two of the following three properties: safety (results are valid and identical at all nodes), guaranteed termination or liveness (nodes that don’t fail always produce a result), and fault tolerance (the system can survive the failure of one node at any point). This is a proven result.”
To prove her point, Kim also referred to Prof. David Mazières, head of Stanford’s Security Computing Group, whose recent study concluded Ripple/Stellar to be safe only under limited circumstances. “Based [on] these findings, we decided to create a new consensus system with provable correctness,” she added. “This effort, led by Prof. Mazières, is underway. His white paper and the accompanying code are expected to be released in a few months.”
Ripple Labs, meanwhile, published their reply on their network’s safety, and other issues, mentioned in Kim’s post. “We look forward to reading Prof. Mazières’ findings once they are published,” they replied, while disagreeing with other network issues mentioned by Kim. The entire post can be read here.
As per the official reports, a notable number of transactions recorded on the previous blockchain were unable to be replayed. Stellar developers have switched to a centralize system until a debug is implemented on the entire network.