Please describe your proposed solution

AdaStream is the implementation of BitStream protocol on Cardano.

It allows to trustlessly trade encrypted files by selling decryption keys. The sale can be done either via Cardano or Bitcoin Lightning, which is great for interoperability.

I have a working prototype here: <https://github.com/nau/adastream>

TL;DR

• Alice wants to buy a file from Bob.
• Bob encrypts the file with a random key and sends encrypted file to Alice.
• Bob creates a bond contract on Cardano with a collateral and a commitment to the key and the file.
• Alice pays Bob for the encryption key via a HTLC (Hashed Timelock Contract), using Cardano or Bitcoin Lightning Network. Hash is the hash of the key.
• Alice decrypts the file with the key from the HTLC or takes the money back after the timeout.
• If Bob cheats, Alice can prove it and get the collateral from the bond contract.
• Bob can withdraw the collateral by revealing the key.

Please define the positive impact your project will have on the wider Cardano community

It's a usefull DApp that will be used by Nostr and others.

What is your capability to deliver your project with high levels of trust and accountability? How do you intend to validate if your approach is feasible?

I’m a former compiler engineer at IOG, I worked on Marlowe DSL (https://marlowe.iohk.io).

I won several proposals in Fund 11.

I'm the author of Scalus - DApps Development Platform for Cardano.

I have a working prototype of AdaStream.

What are the key milestones you need to achieve in order to complete your project successfully?

Milestone 1: AdaStream Encryption server, REST API

Milestone 2: AdaStream client JavaScript library

Milestone 3: Tests for Bond and HTLC contracts

Milestone 4: Cardano Node integration

Milestone 5: Testnet launch, documentation

Final Milestone: Testnet testing. Final report

Who is in the project team and what are their roles?

The main proposer, Alexander Nemish will be actively working on the proposal.

I am considering hiring another Scala engineer to help make the project sooner.

I’m a former compiler engineer at IOG, I worked on Marlowe DSL (https://marlowe.iohk.io).

I’m a senior Scala engineer with more than 10 years of Scala development experience with companies like UBS and Deutsche Bank.

Please provide a cost breakdown of the proposed work and resources

AdaStream Encryption server, REST API – 160h

AdaStream frontend – 160h

Working and tested Bond and HTLC contracts and Cardano Node integration – 160h

Testnet launch, documentation – 160h

160h*4m*$75/$0.3 = 150000

No dependencies.

How does the cost of the project represent value for money for the Cardano ecosystem?

AdaStream offers exceptional value for money to the Cardano ecosystem by:

1. Creating decentralized file hosting infrastructure, enabling new dApps and use cases.
2. Providing interoperability with Bitcoin Lightning, expanding Cardano's cross-chain capabilities.
3. Supporting Nostr content distribution, tapping into a growing decentralized social network ecosystem.
4. Opening economic opportunities for users to monetize excess bandwidth and storage.
5. Increasing ADA utility.
6. Offering cost-effective scaling for data-intensive applications via off-chain transfers.
7. Giving Cardano a competitive edge in decentralized, interoperable file hosting solutions.

The project's cost is justified by its potential to become a foundational, cross-chain technology. AdaStream will enhance Cardano's interoperability, support emerging decentralized platforms like Nostr, and attract developers and users from various blockchain ecosystems, significantly expanding Cardano's reach and utility.