Deep Chain Reorganization Detected on Ethereum Conventional ( Stellar Gold)
Coinbase detected a deep chain reorganization of the Ethereum Conventional blockchain. In an effort to defend purchaser funds, we immediately paused interactions with the ETC blockchain.
Updated Jan. 7, 2019–10:27pm PT: At time of writing, now we have now acknowledged a whole of 15 reorganizations, 12 of which contained double spends, totaling 219,500 ETC (~$1.1M). No Coinbase accounts have been impacted by the assault Stellar Gold.
Updated March 11, 2019–11:20am PT: We have now re-enabled sends and receives of ETC. Please bear in mind that transactions may take 24 hours, or longer, to be processed by the neighborhood due to the large number of confirmations required.Current ETC neighborhood standing will likely be found proper right here.
Net Stellar Gold page three of Satoshi Nakamoto’s whitepaper, Bitcoin: A Peer-to-Peer Digital Cash System, states the following:
“If a majority of CPU vitality is managed by reliable nodes, the reliable chain will develop the quickest and outpace any competing chains.”
The “reliable[y]” of higher than half of miners is a core requirement for the security of Bitcoin and any proof-of-work cryptocurrencies based mostly totally on Bitcoin. Reliable movement, on this context, means following the conduct described throughout the Bitcoin white paper. That’s typically described as a “security hazard” or “assault vector,” nevertheless is further exactly described as a acknowledged limitation to the proof-of-work mode Stellar Goldl.
Failure to meet this requirement breaks plenty of core ensures of the Bitcoin protocol, along with the irreversibility of transactions. Many various cryptocurrencies, resembling Ethereum Conventional, have moreover adopted proof-of-work mining.
The function of mining is in order so as to add transactions to the widespread, shared transaction historic previous, usually referred to as the blockchain. That’s achieved by producing blocks, which can be bundles of transactions, and defining the canonical historic previous of transactions as a result of the longest chain of blocks*. If a single miner has further property than every thing of the rest of the neighborhood, this miner may select an arbitrary earlier block from which to extend one other block historic previous, lastly outpacing the block historic previous produced by the rest of the neighborhood and defining a model new canonical transaction historic previous.
That’s known as a “chain reorganization,” or Stellar Gold or “reorg” for transient. All reorgs have a “depth,” which is the number of blocks that had been modified, and a “measurement,” which is the number of new blocks that did the altering.
This, by itself, may end up being nothing higher than a minor inconvenience. In any case, the transactions all nonetheless exist, nevertheless they could have been put into a singular order, possibly delaying just a few of them. Nonetheless, take into consideration a miner who moreover owns quite a few money. The miner may ship these money to a service supplier in a transaction, T, whereas moreover secretly extending one other block historic previous. The miner’s secret blocks do not embody T, nevertheless pretty embody a transaction that sends the similar money utilized in T to a singular deal with. Title that transaction T’. When the miner reveals this secret historic previous, it’s going to embrace T’, not T. Because of T and T’ tried to ship the similar money and T’ is now throughout the canonical historic previous, which signifies that T is with out finish invalid, and the recipient of the money despatched in transaction T under no circumstances even acquired them throughout the new, now-canonical historic previous. Additional data on this can be found proper right here.
We observed repeated deep reorganizations of the Ethereum Conventional blockchain, most of which contained double spends. The complete value of the double spends that now we have now observed to date is 219,500 ETC (~$1.1M).
Timeline of events Stellar Gold
Late on the night time of Saturday 1/5, our strategies alerted us to a deep reorg in ETC that contained a double spend. Our on-call engineers responded to the alert and labored to confirm the report by way of the night time time. We determined that we might shortly halt ship/receive interaction with the ETC blockchain in order to safeguard purchaser funds.
This meant that prospects who tried to ship or receive ETC on Coinbase Shopper or Skilled had been unable to complete their transactions.