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CosmoVoting

Akash Kumar

IIT Bombay

​

Smit Rajput

IIIT Vadodara

​

Tezan Sahu

IIT Bombay

​

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Elections in India

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Facts and Figures, Lok Sabha Elections 2014

Population eligible to vote 900 million

Intra-India migrant population which didn’t vote: 281 million

Approx. 30%

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Long time in

Queues

Lengthy Voting

+ Counting Process

Large population�is migrant

Problems

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Why not a solution until now?

anonymity

Transparency

Security

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Voting

Blockchain

Decentralized Voting System

Solution

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Processes

Registration

Voting

Counting

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Entities Involved

Voter

Political Parties

Constituencies

ECI

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Registration

The voter uploads

Information on

Online portal

Verification done by

ECI

Voter UUID hash Created

a mapping of hash to kycDone made true on blockchain

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Voting

Registered Voters

Logins with OTP & UUID

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Voting

Registered Voters

Logins with OTP & UUID

UUID_hash is checked

from the registration done

on the blockchain

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Voting

Registered Voters

Logins with OTP & UUID

Selects the party

for the vote

UUID_hash is checked

from the registration done

on the blockchain

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Voting

Registered Voters

Logins with OTP & UUID

Selects the party

for the vote

UUID_hash is checked

from the registration done

on the blockchain

party_hash is created

combining party_id with

a random_number

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Voting

Registered Voters

Logins with OTP & UUID

Selects the party

for the vote

Contract is

Updated with the vote

UUID_hash is checked

from the registration done

on the blockchain

party_hash is created

combining party_id with

a random_number

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Voting

Registered Voters

Logins with OTP & UUID

Selects the party

for the vote

Contract is

Updated with the vote

UUID_hash is checked

from the registration done

on the blockchain

party_hash is created

combining party_id with

a random_number

Transaction is completed

on blockchain

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Counting

Chief Election Officer

concludes the voting

3 way authentication

+ decryption

Run the vote_count

function

Vote count declared

Elections complete

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Benefits

Faster Elections

More voters vote as it can

be done from anywhere

Anonymity for Voter

Trust

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The Way Forward

Replace the postal voting system

Will result in increasing awareness among citizens, increasing voter turn out

Can be conducted in parallel with the normal elections. Schools’ computer labs can be utilised as polling booths

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Future Prospects

MnC elections

Co-operative societies’ elections

Integration with services like civic and decentralized oracles

City wide elections

Using Sovrin network for decentralized identity

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How do we ensure the anonymity and secrecy of vote on a public blockchain?

Diving deep into Cryptography

​

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Voting

5 parameters generated on client side :

​

  • constituency
  • uuid_hash
  • party_data_hash
  • party_data_encrypted
  • vote_hash

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Constituency

Constituency the person belongs to

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uuid hash

voter’s adhaar number

Hash function

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uuid hash

voter’s adhaar number

Hash function

UUID Hash

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Vote hash

voter’s adhaar number

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Vote hash

voter’s adhaar number

Salt added by user. This is to be remembered to verify vote

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Vote hash

voter’s adhaar number

Hash function

Salt added by user. This is to be remembered to verify vote

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Vote hash

voter’s adhaar number

Hash function

Vote hash.

Salt added by user. This is to be remembered to verify vote

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party data hash

voter’s chosen Party

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party data hash

voter’s chosen Party

Salt added by a random generator. This need not be remembered

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party data hash

voter’s chosen Party

Hash function

Salt added by a random generator. This need not be remembered

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party data hash

voter’s chosen Party

Hash function

Party data hash.

Salt added by a random generator. This need not be remembered

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Public-Private Key Pair

Publlic Key

Private Key

This needs to be kept safe till the end of election

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party data encrypted

voter’s chosen Party

same Salt which was used to generate party data hash

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party data encrypted

voter’s chosen Party

Encryption Algorithm

Salt added by a random generator. This need not be remembered

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party data encrypted

voter’s chosen Party

Encryption Algorithm

Salt added by a random generator. This need not be remembered

Publlic Key

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party data encrypted

voter’s chosen Party

Encryption Algorithm

Party data encrypted.

Salt added by a random generator. This need not be remembered

Publlic Key

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Registering Vote

Transaction data

Constituency

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Registering Vote

UUID Hash

Transaction data

Constituency

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Registering Vote

Vote hash.

UUID Hash

Transaction data

Constituency

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Registering Vote

Party data hash.

Vote hash.

UUID Hash

Transaction data

Constituency

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Registering Vote

Party data encrypted.

Party data hash.

Vote hash.

UUID Hash

Transaction data

Constituency

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Registering Vote

Smart contract on the blockchain

Party data encrypted.

Party data hash.

Vote hash.

UUID Hash

Transaction data

Constituency

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In smart Contract

UUID Hash

Check if the person have voted before or not

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in smart contract

A mapping of constituency to array of vote data is generated

Constituency

vote data

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in smart contract

A mapping of constituency to array of vote data is generated

Constituency

vote data

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in smart contract

A mapping of constituency to array of vote data is generated

Constituency

vote data

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Decryption

Party data encrypted is sent

Smart Contract

Oracle

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Decryption

Party data encrypted is sent

Smart Contract

Oracle

Oracle decrypts the data using private key

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Decryption

Party data encrypted is sent

Smart Contract

Oracle

Oracle decrypts the data using private key

Party Data

Private key

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Decryption

Party data encrypted is sent

Smart Contract

Oracle

Party Data

Party Data is signed by the oracle and sent back

Signed Party Data

Private key

Oracle decrypts the data using private key

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Verification

Decrypted Party Data

Hash function

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Verification

New Party data hash.

Decrypted Party Data

Hash function

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Verification

New Party data hash.

This check makes sure there is no data manipulation by the oracle

Decrypted Party Data

Hash function

Party data hash.

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chosen party extraction

Decrypted Party data

Salt previously added by a random generator. Not needed

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chosen party extraction

voter’s chosen Party

Decrypted Party data

Salt previously added by a random generator. Not needed

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in smart contract

A mapping of constituency to party to array of vote hashes is generated

Constituency

vote hash

Party A

Party B

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in smart contract

A mapping of constituency to party to array of vote hashes is generated

Constituency

vote hash

Party A

Party B

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in smart contract

A mapping of constituency to party to array of vote hashes is generated

Constituency

vote hash

Party A

Party B

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in smart contract

A mapping of constituency to party to array of vote hashes is generated

Constituency

vote hash

Party A

Party B

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in smart contract

A mapping of constituency to party to array of vote hashes is generated

Constituency

vote hash

Party A

Party B

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in smart contract

A mapping of constituency to party to array of vote hashes is generated

Constituency

vote hash

Party A

Party B

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Counting

Chief Election Officer

concludes the voting

Run the vote_count

function

Calculate length of arrays to decide the winner

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Verification of vote

voter’s adhaar number

Hash function

Vote hash.

Salt added by user initially

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Verification of vote

Vote Hashes are made public at the end of election

Constituency

Party A

Party B

Matched

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CosmoVoting

Thank You

Akash Kumar

IIT Bombay

​

Smit Rajput

IIIT Vadodara

​

Tezan Sahu

IIT Bombay

​

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Pseudo Code

Voting process :

�On the client side :

​

Parameters generated:

  • Constituency

​

  • Uuid_hash :  Hash(adhaar number)

​

  • Party_data_hash : Hash(partyID||random_no)

​

  • Party_data_encrypted : public_key_encryption((partyID||random_no), public_key)

​

  • Vote_hash = Hash(uuid || security_token)

​

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Pseudo Code

In smart contract:

​

Check if:

  • Person’s kyc is done
  • Person has voted before or not
  • The vote is being registered only during the voting phase

�Once checking is done, store the data in the following manner:

�Contract :

​

Vote_data[Constituency][{votedata1},{votedata2},{votedata3}..]

 

vote data = {

Vote_hash

Party_data_hash

party_data_encrypted

}

� �

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Pseudo Code

Decryption process :

​

The decryption oracle loops through the voting data, decrypts the data

and sends back the plain text.

�Decrypter                    <== Contract

          (constituency, index)

�Decrypter                    ==> Contract

(constituency, index, plaintext(partyID||random_no))

��In the Contract:

   Check if:

      Hash(plaintext) == Party_data_hash (Hash(partyID||random_no))

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Pseudo Code

The last step makes sure there is no manipulation of vote data by the decryption oracle.

�Now, use the party ID, to generate vote hash arrays :

​

we have the following data:� constituency

party ID

vote hash

�Contract :

​

Vote_hashes [Constituency][partyID][votehash1, votehash2,...]

​

��

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Pseudo Code

Vote Calculation process :

�EC Head            ==> Contract: calculateVotes ()

        

calculateVotes() :

​

Loop across constituencies :

Loop across party ids :

Number of votes = the array length of vote hashes

Check which party have highest votes�Store the winner as winner[constituency] = partyID with max votes

​

//done

�Here no entity can manipulate the calculation of votes.

�Later election commission can make public the array of

vote hashes corresponding to every party in every constituency.

��

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Pseudo Code

After Election :

�Voter :

�Uuid + security token (chosen at the time of voting) ==> vote hash

�Go to publicly available list of vote hashes => check vote

hash belong to the array of the party he voted for

�