The Constantinople hard fork which was scheduled to take place on January 15 was halted after a vulnerability was found among one of Ethereum Improvement Proposals. The hard fork was a way to implement changes across the entire Ethereum blockchain.
Chain Security, the firm which discovered the vulnerable, noted that the planned Constantinople hard fork introduces cheaper gas cost for certain operations. But:
As an unwanted side effect, this enables reentrancy attacks when using [transfer or send functions] in Solidity smart contracts. Previously these functions were considered reentrancy-safe, which they aren’t any longer.
The firm continued to note that the effect of the reentrancy is that:
Two parties can jointly receive funds, decide on how to split them, and receive a payout if they agree.
The attacker can establish a loop from which they siphon Ethereum coins from a smart contract.
As noted by Cointelegraph, the attacker will all through be using “false data about the malicious actor’s actual ETH balance.”
The Constantinople hard fork coordinator, Afri Schoedon, indicated that the reentrancy security vulnerability is being worked on by developers. The coordinator said that further directions will be availed on Friday after a call with all core developers.
Schoedon made it clear that the Constantinople hard fork “will not happen this week.”
While speaking to Bloomberg, Lane Retting, Ethereum core developer, said that although it is being called a hard fork, Constantinople, “of all the hard forks in the history of Ethereum, it’s probably the least eventful one.”
The biggest effect that the Constantinople hard fork will bring is slashing what miners earn after confirming transactions on the Ethereum blockchain. Currently, the miners earn 3 ETH coins per block. When the Constantinople hard fork becomes active, miners will get 2 ETH coins per block.
With the reduction of mining rewards, do you think the Constantinople hard fork will force miners to stop supporting the Ethereum blockchain?
Let us know your thoughts in the comments section below.