This article was compiled and organized by BlockWeeks
Gabe Rodriguez of Anza, the core development team of the Solana validator client, submitted a Solana Improvement Document (SIMD) on November 5, which is the formal process for modifying the network's protocol. The proposal plans to formally abolish the durable nonce mechanism.
The so-called durable nonce is a stored value kept in a dedicated account, used to replace the "recent blockhash"—that is, the short-lived block reference that every Solana transaction typically carries. Its purpose is to allow a transaction to be signed now and broadcast on-chain much later.
What Exactly Does SIMD-0723 Change
According to SIMD-0723, once this change is activated, "every transaction must carry a recent blockhash." And this reference expires after 150 blocks, at which point the transaction can no longer be put on-chain. The instructions in Solana's built-in System Program used to initialize, advance, and upgrade nonce accounts will be shut down; the two instructions that allow account owners to withdraw funds or reassign control will remain available. Existing accounts will not be touched.
A submission on November 6 added a timeline: a migration window of at least six months, counted from the submission date of November 5; the draft explicitly states that this feature "will not be activated on mainnet-beta (the Solana mainnet) before 2027-05-05." The proposal's status is currently still Draft, and the corresponding pull request has not yet received any approvals. The bot in the repository listed the conditions required for merging: approval from one Anza team member and one member of Jump Crypto's Firedancer team (which is responsible for another independent validator client).
Custodians and Exchanges Called Out
The draft points out that any entity that signs a transaction now but broadcasts it only after the 150-block expiry must redo the process; and it specifically calls out custodians and exchanges—whose approval processes on air-gapped (non-networked) machines may last longer than this window.
In January of this year, during the initial discussion, one participant listed the keys controlling the issuance rights of USDC and USDT (that is, the mint authority) as one of the important users of this feature. Michael Gutkin of Fireblocks wrote in March that the company "manages millions of Solana wallets" and believed that "abolishing durable nonce seems to be the right direction." But he added that if there is no compatible bridging for account migration (for example, a solution that wraps pre-signed transactions), "we believe that at institutional scale, 12 months is the minimum viable period." SIMD-0723 rejected such a wrapping solution and offers only at least six months.
Two Alternatives Officially Offered
The proposal points to two alternative paths: Anza's Programmatic Signer and Blueshift's Vector. In both solutions, the account owner delegates authority to a program-derived address (PDA)—an account controlled by a program rather than a private key—then signs the authorization offline and gives the signature to a third party (a relayer), and the program verifies the signature on-chain transaction by transaction before executing the instruction.
As of November 9, the draft's author Rodriguez had submitted 136 commits to the Programmatic Signer repository, which, according to GitHub contributor data, is the most among multiple contributors. The draft also warns: "a failed submission is not a revocation."
A History of Failures and Extreme Concentration of Fees
The SIMD cites a series of failure cases, including an incident in 2022: validators processed a failed transaction through both the standard blockhash path and the nonce path at the same time, causing the mainnet to stall for about 4.5 hours.
Data released by Max Resnick in June showed that within a certain epoch (Solana's fixed block interval), nonce transactions accounted for about 3.1% of all transactions, yet contributed about 30% of the priority fee (that is, the optional tip used to speed up processing). According to his statistics, among the 103,672 accounts that paid fees for nonce transactions, 555 accounts contributed 97.5% of them.
The Shadow of the Drift Incident
It is worth noting that the full text of the SIMD does not mention Drift. This perpetual contract exchange lost about $295.7 million on April 1 by its own account, and in its recovery plan it called the durable nonce attack surface "a core part of why the April 1 exploit was able to be executed." There were previously reports suggesting the incident may be linked to North Korea, and Drift also published claim arrangements related to recovery tokens.
The Six-Month Countdown and Stacked Upgrade Pressure
The key issue is: the six-month clock starts from the date the draft is published, not from the date the alternatives are ready. As of November 9, the Programmatic Signer repository is still marked as "under construction."
This means custodians must advance this migration while also dealing with other recent core changes, such as the Alpenglow consensus switch and the change expanding the transaction limit to 4,096 bytes.
