THREAT - The public/private key of the election is changed by the Adversary

[chenchanglew]

Scenario

When a user wants to cast a ballot, the frontend server will request the election public key from a blockchain node. And the ballot will be encrypted using the public key.
However, if the frontend requests the public key from a compromised blockchain node, the adversary can reply with a fake public key to the user. Then it can decrypt the ballot if the user uses the public key for the encryption.

Source

“web/frontend/src/pages/ballot/Show.tsx” function sendBallot
“pubKey” is derived from the function “web/frontend/src/components/utils/useElection.tsx” to use pctx.getProxy() for the election info.

Breaking Property

Confidentiality, Integrity

Risk

CVSS Score: 5.8/10

Mitigation

Frontend receives election public keys from at least ⅔ of the nodes.
Frontend reports/sends alert to the D-voting community when releasing there is a different public key.