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Tutorial: Confidential Voting

Pre-Alpha Disclaimer: This is an early pre-alpha release for exploring the SDK and starting development only. There is no real encryption — all data is completely public and stored as plaintext on-chain. Do not submit any sensitive or real data. Encryption keys and the trust model are not final; do not rely on any encryption guarantees or key material until mainnet. All interfaces, APIs, and data formats are subject to change without notice. The Solana program and all on-chain data will be wiped periodically and everything will be deleted when we transition to Encrypt Alpha 1. This software is provided “as is” without warranty of any kind; use is entirely at your own risk and dWallet Labs assumes no liability for any damages arising from its use.

This tutorial builds a complete confidential voting program on Solana using Encrypt. Individual votes are encrypted – nobody can see how anyone voted – but the final tally is computed via FHE and can be decrypted by the proposal authority.

What You Will Build

A Solana program with five instructions:

InstructionDescription
create_proposalCreates a proposal with two encrypted-zero tallies (yes, no)
cast_voteAdds an encrypted vote to the tally via FHE computation
close_proposalAuthority closes voting
request_tally_decryptionAuthority requests decryption of yes or no tally
reveal_tallyAuthority reads decrypted result and writes plaintext to proposal

How It Works

  1. The authority creates a proposal. Two ciphertext accounts are initialized to encrypted zero (EUint64).
  2. Each voter provides an encrypted boolean vote (EBool): 1 = yes, 0 = no.
  3. The cast_vote_graph FHE function conditionally increments the correct counter:
    • If vote == 1: yes_count += 1, no_count unchanged
    • If vote == 0: no_count += 1, yes_count unchanged
  4. The tally ciphertext accounts are updated in-place (update mode) – the same account serves as both input and output.
  5. A VoteRecord PDA prevents double-voting. Its existence proves the voter already voted.
  6. After closing, the authority requests decryption and verifies the result against a stored digest.

Key Concepts Covered

  • #[encrypt_fn] – writing FHE computation as normal Rust
  • Plaintext ciphertext creation – initializing encrypted zeros via create_plaintext_typed
  • Update mode – passing the same account as both input and output to execute_graph
  • Digest verification – store-and-verify pattern for safe decryption
  • EncryptTestContext – testing the full lifecycle in a single test

Framework Variants

The tutorial uses Pinocchio for maximum CU efficiency. Equivalent examples exist for all three frameworks:

FrameworkSource
Pinocchiochains/solana/examples/confidential-voting-pinocchio/
Anchorchains/solana/examples/confidential-voting-anchor/
Nativechains/solana/examples/confidential-voting-native/

Prerequisites