Faster Blocks, Stronger Security, Improved Storage: Tallinn is Live!
The 20th Tezos Protocol Upgrade is Live!
4 minute read
On January 24th 2026, at 16:06:56 UTC, the Tezos blockchain successfully activated the Tallinn protocol upgrade on Mainnet at block #11,640,289.
With Tallinn, the Tezos community celebrates its 20th protocol upgrade! That is, 20 evolutions of the Tezos blockchain, proposed, adopted, and seamlessly activated by the ecosystem through on-chain governance, underscoring Tezos’ ability to adapt to changing demands without disruptions.
Developed by Nomadic Labs, Trilitech, and Functori, the Tallinn upgrade brings three main improvements:
6-second block time: Lower latency and faster finality on Layer 1.
All bakers attesting every block (once ≥50% of bakers use tz4 addresses): Stronger security, more predictable rewards, and leaner consensus.
The Address Indexing Registry: Improves storage efficiency by up to 100x for Michelson apps.
For more details, see the Tallinn announcement post.
6-second block time #
In another push forward on the Tezos X roadmap, Tallinn reduces Layer 1 block time from 8 seconds to 6 seconds. Finality on Layer 1 (two blocks) is now achieved in just 12 seconds.
Besides a smoother overall experience of using Layer 1, the lower block time also benefits Etherlink, as data publication for Layer 2 is secured through inclusion in L1 blocks.
Decentralization and censorship resistance are put front and center as always. The 6-second block time is achieved while preserving a low barrier to entry for network validation in terms of hardware requirements.
All bakers attest every block (once at least 50% use tz4 addresses) #
Tallinn also enables all bakers attesting to every block, instead of only a subset of bakers.
It means stronger security and more predictable rewards, and also lightens the load on nodes, opening the door to further block time reductions.
The feature relies on the BLS signature scheme behind tz4 addresses, which enables hundreds of attestations to be aggregated into a single signature in each block.
Therefore, this change does not activate immediately, but only once 50% of bakers adopt tz4 addresses for consensus operations. This is measured as the percentage of individual baker operations and not the share of total stake. Please also note:
No baker is left behind. Baking from tz1/tz2/tz3 addresses remains possible, also after activation.
Only the consensus key needs to be tz4. The manager key and public address can remain the same.
Once active, the feature stays enabled, even if participation dips later.
For switching to tz4, keep in mind that current Ledger hardware signers cannot produce tz4/BLS signatures fast enough for Tezos consensus needs. Tz4-capable alternatives include the Tezos RPi BLS Signer, TezSign, and Signatory.
Address Indexing Registry #
Tallinn enables up to 100x lower storage footprint for enterprise-scale apps and large NFT ledgers using the Michelson runtime.
This is thanks to the Address Indexing Registry which eliminates redundant address data in contract storage. Existing apps will need to be updated to take advantage of this feature, but the payoff should be worth it for any app maintaining a large ledger of addresses, in terms of improved cost-efficiency.
Broad adoption of this feature will also mean slower growth in network-wide storage footprint and higher potential throughput.
Smooth progress, thanks to the ecosystem #
The Tallinn protocol upgrade is another forkless step forward in making Tezos faster, more secure, and optimized for enterprise-scale use cases. As always, with no compromise on decentralization.
It is possible due to the constructive involvement from bakers and ecosystem teams. Their testing, feedback, and careful implementation are what enables Tezos to stay at the forefront of blockchain technology.
Welcome to Tallinn!