Midnight Korea Hackathon Winners Target Grants, Housing and Supply Chains

Midnight’s October 27 network update highlighted three winning projects from its Korea Hackathon, where 38 teams submitted working decentralized applications built with Compact, the network’s smart contract language. The competition’s September development phase culminated in an October 2 showcase in Seoul involving CertiK and Seoul Fintech Lab.

Three Applications for Midnight’s Privacy Technology

JustEnough focuses on verifying eligibility for grants and public programs without requiring applicants to disclose their personal documents to each program. Safejeonse addresses a separate information problem in housing: checking rental deposit safety while keeping other tenants’ financial details private.

Veilance applies private verification to supply chains. Midnight describes it as a tracker for proving recycled material content for EU regulatory requirements without exposing suppliers’ trade secrets. Its developer, Juho Lee, describes a demonstration connecting mines, refiners, and battery manufacturers through digital provenance certificates. Those certificates carry information that different participants can verify without receiving the full transaction record.

Verifying Eligibility and Preventing Duplicate Claims

JustEnough’s project documentation describes a process in which an issuer first attests to an applicant’s attributes. The applicant then generates a zero-knowledge proof showing that a private credential meets a program’s published conditions. An example combines an age range, residence in Seoul, and enrollment status.

The contract also records a program-specific identifier, called a nullifier, to reject repeat claims using the same credential. This separates eligibility verification from duplicate-claim prevention while avoiding disclosure of the applicant’s underlying attributes. The prototype uses a demonstration issuer account; the issuer still knows the information it attests to.

Veilance uses a related mechanism for provenance certificates. According to Lee, certificates are recorded through cryptographic commitments, and transfers leave a nullifier that prevents the same certificate from being reused. Consumers, procurement teams, and regulators can check different conditions, including certified origin, holder authorization, and whether a carbon grade falls below a specified threshold. Original certificates are encrypted for their recipients.

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Demonstrations and Further Development

The projects’ documentation distinguishes their demonstrations from broader deployment. Lee describes a local development-network scenario for Veilance covering certificate issuance, transfer, verification, and rejection of a reused certificate. The implementation includes a web interface and a backend for managing participating wallets.

JustEnough offers a browser simulator that lets users explore credential issuance, eligibility decisions, and rejected duplicate applications without installing a wallet. Its documentation specifies that actual zero-knowledge proofs are generated in the network build. Planned extensions include mobile wallet access, additional eligibility rules, and an independent circuit audit. Moving beyond the demonstration issuer would require integration with trusted credential providers and support for credential revocation and expiration.