DESCRIPTION OF EVENTS
"Electronic transactions for all. Without censorship or restrictions." "Designed for the decades to come, not just for tomorrow. To be used by anyone, anywhere." "Grin was launched on January 15th, 2019." "It's very young and experimental. Use at your own risk!" "Grin, which was the first cryptocurrency to test privacy protocol MimbleWimble and drew an estimated $100 million in venture capital to mine it, was once called “Bitcoin 2.0.”"
"The most recent attack on a proof-of-work cryptocurrency dates back to November 2020. Grin, another privacy coin that suffered a 51% attack on its blockchain network. The Grin team built its token on the Mimblewimble protocol."
"According to a Nov. 7 tweet from crypto mining group 2Miners, an unknown group accumulated 57.4% of the total hash power of the Grin (GRIN) network on Saturday evening. 2Miners only had control of 19.1% of GRIN’s hash power, while sparkpool miners came in third at 18.9%."
"Grin Network Is Under the 51% Attack!" "Payouts are stopped. Please mine at your own risk only because the new blocks could be rejected."
“Important notice,” the web portal’s warning reads. “The Grin network hashrate has increased considerably over a short period of time. Notably, this coincides with the Nicehash rate doubling in this time with well over 50% of the network hashrate currently outside of known pools. Considering these circumstances it is wise to wait for extra confirmations on transactions for payment finality.”
"Data from GrinScan shows the attackers were able to reorganize at least one forked block, at 23:17 UTC on Nov. 7. The unknown mining group has also increased its control since Saturday, commanding 58.1% of GRIN’s hash rate at the time of publication. 2Miners’ has risen to 24.6%, while sparkpool miners’ has dropped to 11.3%."
"When a group of miners controls more than half of a network’s mining power, it can affect the organization of blocks, potentially causing volatility in the token price and disrupting confidence in the blockchain. However, a mining group having control of 51% or more of a network’s hash rate does not necessarily mean it has ill intentions — sparkpool has had up to 60% of the network’s hash power before and reportedly did not interrupt the production of new GRIN blocks."
"GRIN coins were down 2.23% to $0.235 at press time." "Currently, the price of grin is trading for $0.233 per coin, and there’s $3.4 million in global trade volume. The price of grin (GRIN) has lost 2.9% during the last 24 hours of trading. Most of the slide is due to the entire market downturn, as the 51% attack threat hasn’t really affected the price much at all this past weekend."
"Crypto Briefing also learned that the Grin team has notified all exchanges about the situation and is working with them to prevent hackers from spending any forked coins."
The Grin token blockchain was 51% attacked after a mining pool managed to gain control of the majority of the hashing power. Transactions were reorganized and it's not clear if any funds were lost.
HOW COULD THIS HAVE BEEN PREVENTED?
51% attacks can be prevented through a mix of increased block confirmation times and setting checkpoints to prevent large-scale reorganizations. This means the exchange will not credit newly deposited funds, and nodes will be prevented from accepting attacking chains.
Privacy-Centric Cryptocurrency Firo Suffers 51% Attack on Its Network – Altcoins Bitcoin News (Oct 18)
Grin (Oct 19)
Grin Community Project Day: all-news related to MimbleWimble (Oct 19)
Privacy Coin GRIN Is Victim of 51% Attack - CoinDesk (Dec 5)
Grin (Dec 5)
Grin network hit with 51% attack while GRIN token remains resilient (Dec 5)
@pool2miners Twitter (Dec 5)
https://www.nasdaq.com/articles/privacy-coin-grin-is-victim-of-51-attack-2020-11-08 (Dec 5)
Grin Network Victim of 51% Attack, Unknown Miner Commands 58% of the Hashrate – Bitcoin News (Dec 5)
Privacy Coin GRIN Suffers 51% Attack, Network Still Vulnerable (Dec 5)
GRIN suffers 51%, but token remains unaffected (Dec 5)