The problem The Sealed Sky solves

The Sealed Sky is a consumer grade timelock encryption tool with easy to use user interface.

It allows to encrypt - seal the content now, decrypt only when a future moment arrives.

Use cases:

• Time capsules at any scale - 30 seconds, a year, a decade.
• Sealed-bid auctions where everyone reveals at the same instant, nobody before.
• Dead-man's switches and posthumous notes, with no trusted custodian holding the key.
• MEV-resistant order submission and time-locked DAO votes.
• Predictions of future that can be undisclosed after the fact.
• Intergenerational messaging - send a message to yourself or your closed ones that becomes legible only in 2030.

The demo website uses TypeScript implementation of the TimeLock library based on Boneh–Franklin's IBE paper.

Complementary part of the project is a Trusted Edge Oracle - small stack that lets you treat a USB Armory (Secure World / TrustZone) as a signing oracle for short, structured payloads. A Node backend re-checks proofs with the same HMAC rule as the Armory, records accepted and rejected runs, and optionally pushes on-chain attestations to Sepolia and surfaces validation through ENS.

It can be used to

• As a proof “This result came from our edge device, not from a browser tab.”
  -Cheaper, clearer audits than “trust our server.”
  -Safer automation with a relayer.
  -Public transparency without dumping your whole database.

Challenges we ran into

Challenges are surprisingly the opposite of what we were used at the hackathons years ago.

We admit utilized AI agent tools (Claude Code, Cursor), they helped us reach to develop proof-of-concepts at paces not possible before, but for us developers, it became complicated to keep track of all the important technical nuances of the proposed solution.

Issues that would need further attention - handling of the K key (there are ways how to tie the message to a specified public address without the need to store the K key safely until the unlock time). If the messages are meant to be unlocked by public, the K key storage is not an issue.