Solana Validators Must Register BLS Pubkey Before VAT Feature Gate Activates This Week

Solana mainnet validators need to register a BLS (Boneh-Lynn-Shacham) public key before the end of this week. Anza Anza's Validator Admission Ticket (VAT, SIMD-0357) is the second of two feature gates rolling out as Alpenglow prerequisites, and it is scheduled to activate on mainnet during the week of July 20, 2026. Once the gate goes live, validators without a registered BLS pubkey are cut from consensus and stop earning inflation rewards.

The first gate, BLS pubkey registration (SIMD-0387), is already active on mainnet, meaning validators can complete registration immediately without waiting for a software update. VAT adds the enforcement layer: from the activation block onward, participation in each epoch's consensus round requires both a registered BLS pubkey and, per the Solana Foundation, a stake rank within the top 2,000 validators.

How to Register a BLS Pubkey on Solana

Registration requires Solana CLI 4.1.0 or higher. Three commands complete the process:

1. Derive the BLS key from your authorized voter keypair:

   solana-keygen bls_pubkey <AUTHORIZED_VOTER_KEYPAIR>
   

2. Authorize the vote account with the BLS variant:

   solana vote-authorize-voter-checked <VOTE_ACCOUNT> <AUTHORIZED_VOTER_KEYPAIR>
   

3. Confirm the key is set:

   solana vote-account <VOTE_ACCOUNT> | grep "BLS Public Key"
   

The third command should return the 48-byte compressed BLS pubkey tied to your vote account. The registration also creates a 96-byte proof of possession on the VoterWithBLS entry, binding the key to the vote account and preventing unauthorized registration. Full registration instructions, keypair handling notes, and troubleshooting steps are at solana.com/upgrades/bls-pubkey-vat.

What the VAT Admission Set Enforces

VAT establishes a hard per-epoch cap of 2,000 validators. Once active, a validator qualifies for the admitted set only if it has a registered BLS pubkey and falls within the top 2,000 by stake weight. Validators outside the admitted set receive no inflation rewards for that epoch, regardless of uptime or vote history.

VAT and the Alpenglow Consensus Switch Are Separate Feature Gates

VAT activating this week does not trigger Alpenglow consensus. Anza engineer Tim Garcia directed validators to the official upgrade page on July 20 to address the common mix-up: VAT and the full consensus switch (SIMD-0326) are separate feature gates. Under VAT, validators continue using the existing on-chain, transaction-based voting system.

BLS pubkeys are required because Alpenglow's Votor algorithm aggregates many validator signatures into a single combined signature off-chain. That aggregation architecture requires BLS keys, which are incompatible with the ed25519 keys Solana currently uses for voting. VAT ensures the key infrastructure is in place network-wide before the consensus switch happens.

After Alpenglow Activates: The 1.6 SOL Epoch Fee

The full Alpenglow consensus switch (SIMD-0326) is planned with Agave 4.3 and targeted for approximately October 2026. When it activates, voting moves off-chain and the Solana Foundation describes a flat epoch fee of 1.6 SOL, burned to the incinerator. The Foundation notes this approximates the roughly 2 SOL per epoch validators currently spend on on-chain voting transaction fees, making the economics broadly comparable for admitted validators at current network conditions.

Anza's bug bounty competition covering Alpenglow consensus components, reported by Solana Compass on July 18, remains open ahead of the planned mainnet deployment.