Private & Permissioned L1s — Access Privacy

Overview

"Private" means two different things. Getting this right drives the whole design.

• Access privacy (Walled Garden): the chain is hidden — only authorized participants can reach the RPC to read anything. Natively supported on Avalanche.
• Data privacy (Encryption): the chain is public, but transaction contents are encrypted (e.g. eERC zk-SNARKs, Zama FHE). Anyone sees that txs happened; contents are hidden.

Most private blockchains use access privacy; some public chains add data privacy. eERC ([[eerc-introduction]]) is the data-privacy tool; this skill is the access-privacy tool.

The three models

Aspect	Permissioned Private	Permissioned Public	Permissionless
RPC access	Restricted endpoints	Public	Public
Data visibility	Authorized only	Anyone	Anyone
Tx submission	Authorized users	Authorized / anyone	Anyone
Contract deploy	Authorized users	Authorized / anyone	Anyone
Validator entry	Permission required	Permission required	Anyone (with stake)
Governance	Centralized/Hybrid	Centralized/Hybrid	Decentralized

How Avalanche implements each

• Permissioned Private L1: fixed validator set (ValidatorManager, [[poa-validator-manager]]) + restricted RPC ([[restrict-rpc-access]]) + write gating ([[l1-transaction-allowlist]], [[l1-deployer-allowlist]]).
• Permissioned Public L1: Proof of Authority with controlled validator additions; public RPC; gated writes.
• Permissionless L1: Proof of Stake; anyone validates by staking.

Choosing the model — questions to ask

1. Regulatory: do you need KYC/AML gating? → permissioned + allowlists.
2. Transparency: must the public audit it? → public RPC (or data privacy via eERC).
3. Trust: closed validator set acceptable, or need economic security? → PoA vs PoS.
4. Participant control: must you control who interacts? → restrict RPC + tx allowlist.

Common Pitfalls

• Confusing the two privacies. A walled-garden L1 still stores plaintext; anyone who gets RPC access reads everything. Combine with eERC for data confidentiality ([[combining-eerc-with-private-l1]]).
• Restricting writes but not reads (or vice-versa). "Private" needs both: restricted RPC (reads) and allowlists (writes/deploys).

AI Agent Prompt

"Act as an enterprise blockchain architect. Classify whether I need access privacy, data privacy, or both, then map my Avalanche L1 to permissioned-private / permissioned-public / permissionless with the concrete restrictions to apply."

References

See references/README.md (academy permissioned-l1s "Blockchain Permissioning", access-restriction course).