eccentricexit
commented
6 years ago Important notes
For future readers interested in blockchain voting systems or otherwise any voting system using electronics: Any high stake voting system such as a nation election MUST be accompanied by a software independent audit trail to have any value. Specially if that voting system involves having devices connected to the internet.
I have been researching trustless voting systems as well and had a proposal that uses similar techniques to provide anonymity to this but is focused on large scale voting systems.
Please read this and tell me if it you think I should create a new issue. Suggestions are also welcome.
Vīsus : High Throughput Decentralized Voting System
Abstract
Many of the current on-chain voting systems provide elegant solutions with features that traditional (client-server) e-voting couldn't deliver. However, most of them are either too expensive or too slow to implement on public chains when high throughput is required. Consortium chains can provide such scalability but require users to trust that authorities won't fork the chain. This restricts trustless voting systems to be used on the main chain by small groups and prevents usage in large scale voting systems such as the ones used to elect presidents and state representatives.
By leveraging security of the Ethereum mainnet and performance of a tindermint child chain it is possible to offload high throughput requirements from the main chain while retaining guarantee that tokens can be withdrawn to the main chain even if the child chain completely halts. By submitting merkle roots of every 2^n blocks we can trade finality to further decrease the cost of maintaining the child chain.
Proof-of-Concept Deliverables
- A token to be deposited to and from the child chain for staking and voting.
- A smart contract to store and manage:
- Merkle roots of block sequences;
- Authorities allowed to submit merkle roots of sequence of finalized blocks;
- deposit(), exit() and challengeExit() functions.
- A child chain client to:
- Collect public keys TXOs from the child chain for ring signatures;
- Calculate stealth addresses for voting;
- Calculate key images.
- Submit transactions
- Transaction discovery and tallying.
Note: PoC will be UTXO based to simplify proof verification on the parent chain.
Procedure
- Election authority buys tokens on a regular exchange.
- Election authority deposits them on the child chain along with candidate's addresses
- Election authority transfers tokens to voters on the child chain.
- Voter ring-signs a transaction transferring their vote to a calculated candidate stealth address. The transaction also includes the voter key image.
- Election authority sunsets the election on the child chain and publishes candidates' view keys.
- Voters may tally the election results themselves
**Note: The tokens stay on the candidates' wallets forever, are considered spent and cannot be withdrawn to the parent chain again. The tokens received by block producers are newly minted tokens from coinbase transactions.
Incentivization
Block producers, validators and stakers will receive tokens proportional to the number of tokens processed in a block such that blocks with 0 transactions provide no reward. In short, the system is a transfer of funds from users/election authorities to the stakers/validators/block producers that maintain the blockchain.
Example: An election where 30.165.500 votes* will be cast in an 8 hour period requires ~1050tx/s Using a 5 second blocktime rewards 5235 tokens to be distributed among stakers per block.
- Population of Chongqing - The Largest city in the world by population.
Challenges
For these plans we must keep in mind that a voting system has requirements that most plasma chains don't need to deal with:
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A voting system is an all-or-nothing game: In a currency related plasma chain, interaction is mostly centered around 2 parties where one side wants to be sure that the other didn't trick him. However in a voting system, your voice being included in the results is not enough: It is important that everyone else is heard correctly.
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Authorization and account handling: The voting system must be protected against sybil attacks and only allow one vote per participant. Furthermore, there must be a mechanism to do account recovery that doesn't require (or allow) a central authority. Luckily, we have uPort being developed. Integrating uPort into visus creates a bridge between traditional institutions and the blockchain to allow for KYC authorization. Authorization is done by sending an authorization message signed with a government authority private key.
If voters loose their private keys they can recover them using uPort's social recovery.
burdges
mariapao
Jake-Gillberg
LouisGrx
Aragon Nest Proposal: Secret voting infrastructure using Ring/Threshold signatures
Abstract
The first Metropolis release, Byzantium, introduced a series of precompiled contracts that made some elliptic curve arithmetic operations available to be used in smart contracts within reasonable gas costs.
These operations allow for great things such as verifying zkSNARKs proofs, as well a way to implementing ring signatures on chain.
Ring signatures are a cryptographic construct that allow a number of keyholders of a particular ring, to sign a message authenticating themselves as part of the group, in a way that it is impossible to determine who in the group signed a particular message, but also detecting if one particular member tries to submit more than one signed messages.
This technology could be used to implement secret voting on-chain with a flow similar to this:
A sign up period, in which all token holders of a particular token can get a key that they can use to vote. This is specially useful for settings in which voting is not stake based and every holder has the same voting rights or small multiples.
A voting period, in which key holders can sign their vote and submit it to the blockchain in a way that it is almost impossible to identify the voter. A Ring Voting smart contract will validate the signature and count the vote if valid.
Deliverables
A smart contract implementation (plus off-chain tooling) to achieve:
Bonus:
As this project will require a significant research effort which will probably result in not yet know facts, these deliverables can be modified for reasonable causes.
Prior art
Grant size
TBD
Application requirements
Development timeline
We intend to make an Aragon app for secret voting using this tech in the first half of 2018.