The problem BlockWhisper solves

In today’s digital age, privacy, and identity crises present significant challenges, particularly within the blockchain space. Despite the promise of decentralization, many systems still expose individuals to risks of identification and retaliation when reporting sensitive information. Existing whistleblowing platforms, such as SecureDrop and GlobaLeaks, primarily cater to individual organizations and do not leverage the potential of blockchain technology to provide a truly decentralized, anonymous, and self-governing reporting system.

BlockWhisper aims to address these gaps by offering a decentralized platform that enables anyone to anonymously share sensitive information without fear of identity exposure, harassment, or legal repercussions. Our platform ensures that no single entity controls the information, thus preventing censorship and promoting transparency. BlockWhisper can ensure full anonymity while maintaining a reputation system. This way, users can build trust in the platform without revealing their identities.

Keywords: Freedom of speech, Anonymity, Decentralization

Challenges you ran into

Throughout the hackathon, we faced several challenges. While we managed to address the critical ones, there are some edge cases that are still open for further investigation.

Enable free transactions Users should not face the issue of having to acquire ETH anonymously for transaction fee funding.

https://eips.ethereum.org/EIPS/eip-2711#sponsored-transactions -> withdrawn https://eips.ethereum.org/EIPS/eip-3074#another-sponsored-transaction-eip -> draft https://eips.ethereum.org/EIPS/eip-4337#paymasters -> draft Solution: We mimic faucets to fund user accounts, thereby alleviating them from the struggle to onramp anonymously.

Decentralized Reputation Scoring Without Public Accounts to Ensure Anonymity: The score is implemented as a snapshot, calculated for any new submission, and attached to the new submission’s data structure utilizing a zero-knowledge proof. Herein, we do not prove exact qualities but abstract ones to avoid identity leaks. A proof could be something like “the anon submitted greater than ten submissions before”, “the anon’s submissions have a mean reputation (upvotes/(upvotes + downvotes)) greater than 50 percent”, “the anon’s worst submission has a score greater than 20 percent” or similar. This effectively supports a feedback cycle—mandatory for any self-governing system—without publicly disclosing an identity or even a pseudonym, which links submissions. We employ the technique of hierarchical deterministic wallets to create single-use wallets that mint a soul-bound NFT as proof of authorship (PoA) over a submission.

Technology used

Frontend: Typescript, Next.js, hCaptcha | Backend: Solidity, Ethereum | ZKP: Circom, snarkjs