Solana makes validator BLS keys live as its admission-ticket gate approaches
BLS registration is active on mainnet, while the Validator Admission Ticket remains a separate step that will limit the admitted set and change how voting costs are collected.
Solana has put the cryptographic preparation for its next consensus system in front of validator operators. The Solana Foundation's upgrade note says BLS public-key registration is live on mainnet, while the separate Validator Admission Ticket feature remains pending ahead of the Agave 4.3 release. The two steps are related, but they are not the Alpenglow consensus switch itself.
BLS keys are needed because Alpenglow's voting design is meant to combine thousands of validator signatures into one compact certificate. Solana's current validators vote with Ed25519 keys, which cannot provide that aggregation. Each operator therefore needs an additional BLS key tied to its vote account before the admission rules change.
A new key, not a new validator identity
The registration flow uses Solana CLI 4.1.0 or later. An operator derives the BLS public key from the authorized voter keypair, registers it against the vote account and checks that the chain has recorded it. The transaction includes a 48-byte compressed public key and a 96-byte proof of possession, which binds the key to the vote account and helps prevent a rogue registration.
Solana describes the change as additive. Registering a BLS key does not replace the authorized voter or require a new vote account. That makes the current step an infrastructure task for operators, even though its consequences arrive later through the validator-set rules.
Admission becomes a scarce network resource
When VAT activates on mainnet, a voting validator without a registered BLS key will be excluded from consensus. The page also describes a 2,000-validator limit for the admitted set. After the full Alpenglow switch, Solana says each admitted voting validator will pay a flat 1.6 SOL per epoch into the incinerator; before that switch, the network continues to use its current voting model and costs.
That makes stake position part of the upgrade story. A validator can complete the cryptographic requirement and still sit outside the active set if it falls beyond the stake-ranked limit for an epoch. The immediate test is operational: whether operators register keys in time, whether the admission list behaves as designed on testnet, and whether Agave 4.3 delivers the consensus transition on its stated path. Delegators may not notice the change in a wallet, but the economics and concentration of validator participation will be visible in the network's operating data.
