EIP-2681: Limit account nonce to 2^64-1
|Authors||Alex Beregszaszi (@axic)|
Table of Contents
Limit account nonce to be between
Account nonces are currently specified to be arbitrarily long unsigned integers. Dealing with arbitrary length data in the state witnesses is not optimal, therefore this EIP will allow proofs to represent the nonce in a more optimized way.
Additionally it could prove beneficial to transaction formats, where some improvements are potentially sought by at least three other proposals.
Lastly, this facilitates a minor optimisation in clients, because the nonce no longer needs to be kept as a 256-bit number.
Introduce two new restrictions retroactively from genesis:
- Consider any transaction invalid, where the nonce exceeds or equals to
CREATE2instructions’ execution ends with the result
0pushed on stack, where the account nonce is
2^64-1. Gas for initcode execution is not deducted in this case.
It is unlikely for any nonce to reach or exceed the proposed limit. If one would want to reach that limit via external transactions, it would cost at least
21000 * (2^64-1) = 387_381_625_547_900_583_915_000gas.
It must be noted that in the past, in the Morden testnet, each new account had a starting nonce of
2^20in order to differentiate transactions from mainnet transactions. This mode of replay protection is out of fashion since EIP-155 introduced a more elegant way using chain identifiers.
Most clients already consider the nonce field to be 64-bit, such as go-ethereum.
The reason a transaction with nonce
2^64-1is invalid, because otherwise after inclusion the sender account’s nonce would exceed
While this is a breaking change, no actual effect should be visible:
There is no account in the state currently which would have a nonce exceeding that value. As of November 2020, the account
0xea674fdde714fd979de3edf0f56aa9716b898ec8is responsible for the highest account nonce at approximately 29 million.
go-ethereum already has this restriction partially in place (
types.txdata.AccountNonceit as a 64-bit number).
Copyright and related rights waived via CC0.
Please cite this document as:
Alex Beregszaszi (@axic), "EIP-2681: Limit account nonce to 2^64-1," Ethereum Improvement Proposals, no. 2681, April 2020. [Online serial]. Available: https://eips.ethereum.org/EIPS/eip-2681.