Anza's Solana (SOL) Proposal SIMD-0723 Targets Durable Nonce End in May 2027

SIMD-0723 Puts an Expiry Date on Every Signature

SIMD-0723, filed on GitHub on November 5 by Gabe Rodriguez of Anza, the team that maintains the network's primary validator software, asks Solana (SOL) to retire the durable nonce, the mechanism that lets a signed transaction bypass blockhash expiry and remain valid weeks after signing. The proposal text is blunt about the effect: once activated, every transaction will require a recent blockhash, whether it is submitted in seconds from a hot wallet or routed weeks later through standards such as Solana Blinks and Actions. The change sits in the base transaction layer rather than the fee market, so readers tracking the Solana (SOL) price will find no supply or staking parameter inside it. The affiliation matters: the author works on the software the network's validators run, giving the filing more force than an outside draft would carry. The motivation is written in losses. In April, an attacker used a durable nonce to pre-sign a transaction against the trading platform Drift, held the signature for more than a week, and then drained at least $270 million; official statements at the time put the loss at $285 million, all of it washed into ETH, and the DRIFT token fell 28% in the aftermath. Drift runs spot trading and perps on the network, which is why the case became the reference point for every custody team on the chain. The proposal never names the exchange. It argues from an incident record instead, citing a 2022 failure in which a single transaction traveled both the blockhash and the nonce path and kept mainnet down for roughly 4.5 hours. That outage came from a bug, not a theft, but the document treats both as symptoms of the same design carrying too much freight. An unexpiring signature, it reasons, removes the chain's last automatic backstop: a transaction that can no longer be submitted.

The mechanics explain who loses what. A normal transaction carries a blockhash bound to recent blocks, and with slot times compressed to about 200 milliseconds, that reference expires in roughly 30 seconds. The durable nonce swaps the aging stamp for one that never goes stale, which is what slow, offline signing pipelines require. The proposal names the exposed group itself: custodians and exchanges using air-gapped signing machines, whose approval flows routinely outlast the 30-second window and whose vaults hold KYC-verified customer funds. For those operators, the draft rewrites an assumption: a withdrawal signed at the start of a multi-day approval chain must reach the network while its blockhash is fresh. Two replacements are on the table, Anza's Programmatic Signer and Blueshift's Vector, both of which verify offline signatures through on-chain programs rather than a nonce account. The draft carries a warning for teams that adopt them: a single failed execution can leave the underlying authorization live, so a failed submission is not a revocation. Usage data shows why the wider network is unlikely to fight for the feature. Researcher Max Resnick's numbers in the proposal's community discussion put durable nonce transactions at about 3% of transaction volume during a June measurement window, against roughly 30% of all priority fees paid. Resnick did not identify who operates those accounts, calling the feature repurposed for durable nonce spam. A sliver of traffic absorbing a third of the priority-fee burden is, by that measure, a subsidy running in reverse. The dates are fixed on paper and soft in practice. Activation on mainnet-beta is written as no earlier than May 5, 2027, with at least six months of migration time from the proposal's November 5, 2026 publication. The Foundation's own deprecation page still reads “no date is set”, and the six-month clock starts only once the replacements are ready. Merging also requires one engineer's sign-off each from Anza and Firedancer, the competing validator client built by Jump.

The 2027 Date Has Two Owners

The security logic is hard to argue with: the indefinite validity that serves a cold-storage workflow served the Drift attacker, and April put a nine-figure price on that gap. Institutions reworking their signing flows can compare the best Solana wallets for self-custody. Execution, not intent, is the open question. Both validator clients that staking operators run must ship support, and if Firedancer lags, May 5, 2027 stops being a sunset and becomes a client-split argument. Positioning adds a market edge: our earlier coverage found futures accounts 78.2% long near $90, and level work sits in our Solana technical analysis. Until Anza and Firedancer both sign the same document, the date inside SIMD-0723 is a target with two owners, and neither has signed it yet.