Removes Accounts Delta Hash
- Idea
- Draft
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Decision brief
Why this proposal matters
With the introduction of the Accounts Lattice Hash (SIMD-215), the merkle-based Accounts Delta Hash is redundant and can be removed.
Proposal at a glance
What changes
- With the introduction of the Accounts Lattice Hash (SIMD-215), the merkle-based Accounts Delta Hash is redundant and can be removed.
Stakeholder map
Who is affected
Builders & client teams Impact unknown
No proposal-specific evidence was found for this group.
Action requirement unknownValidators & operators Medium impact
Only validators will be impacted, and their performance will improve since the merkle-based hashing of modified accounts per block will no longer be performed.
Action requirement unknownUsers & stakers Impact unknown
No proposal-specific evidence was found for this group.
Action requirement unknownGovernance & ecosystem Impact unknown
No proposal-specific evidence was found for this group.
Action requirement unknownExact source revision
Full proposal document
f1f6c8b05dc2Summary
With the introduction of the Accounts Lattice Hash (SIMD-215), the merkle-based Accounts Delta Hash is redundant and can be removed.
Motivation
This SIMD follows on from SIMD-215, and shares its motivation:
The main goal is to scale Solana to billions accounts
When a block is done being processed, it is frozen. The bank hash is calculated during the freezing process, and includes calculating the Accounts Delta Hash. The Accounts Delta Hash is the merkle-based hash of the accounts modified in this block. As established in SIMD-215, merkle-based hashing of accounts hinders scaling. And since SIMD-215 added the Accounts Lattice Hash, which is a hash of the total account state, the merkle-based hash of only the accounts modified per block is redundant. Therefore the Accounts Delta Hash can be removed from the bank hash entirely.
New Terminology
None.
Detailed Design
Remove the Accounts Delta Hash from the Bank Hash.
Alternatives Considered
None.
Impact
Only validators will be impacted, and their performance will improve since the merkle-based hashing of modified accounts per block will no longer be performed.
Security Considerations
None.
Backwards Compatibility
Incompatible. This changes the bank hash, thus changing consensus.
Evidence graph
Related proposals and rollout
One or more sources are unavailable.
Upstream review record
Upstream discussion & review
GitHub review is editorial context, not evidence of on-chain support, voting, or outcome.
PR #223 · merged SIMD-0223: Removes Accounts Delta Hash 1 comments and reviews · Jan 26, 2026One issue with this (as well as 215) is that we won't be able to build light clients for bridging purposes. Right now, one can use the accounts epoch hash to update the validator balances and build a light client for verifying a given block, and then use opening proofs of the accounts delta hash to prove certain bridging actions have occurred. By removing the accounts delta hash and migrating the accounts epoch hash to LtHash which doesn't support inclusion proofs, this will no longer be possible. A solution here is to keep supporting the account delta hash (or allow some way for an account to optionally have its deltas merklized to a different hash at an additional cost) and to add a valida
GitHub ↗Provenance
Evidence & technical details
Rollout or chain data, source revisions, freshness and integrity. 2
Provenance
Evidence & technical details
Rollout or chain data, source revisions, freshness and integrity.SIMD
Deployment Status
LTdLt9Ycbyoipz5fLysCi1NnDnASsZfmJLJXts5ZxZzExact source revision
Sources & integrity
- Proposal document pinned_commit_blob
f1f6c8b05dc205552d3c290a854a438392701107 - simd-document document · stale · Oct 16, 2026
f1f6c8b05dc205552d3c290a854a438392701107
One or more sources are unavailable.
simd.watch community discussion · SIMD-0223
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