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Share confidential documents by using Secret Network - Privacy as a Service #123

Open akugone opened 11 months ago

akugone commented 11 months ago

🛡️ Share confidential documents by using Secret Network - Privacy as a Service

Secret Network is introducing a groundbreaking functionality to utilize its blockchain as a service. This innovation offers new possibilities, such as the ability to execute contracts on Polygon while leveraging the privacy features of Secret Network. This approach ensures the security of a primary blockchain while harnessing the privacy capabilities of Secret Network for external computations.

In our proposal, we aimed to create a robust mechanism for securely sharing documents on the blockchain with specific recipients. This solution addresses a critical need for businesses and decentralized autonomous organizations (DAOs) seeking to share sensitive administrative and confidential data to a selected audience. Currently, the challenge lies in sharing documents on-chain while safeguarding the privacy of users. We firmly believe that Secret Network's cutting-edge technology can effectively address this use case by enabling individuals to share documents with the assurance of privacy and data encryption, thus redefining the way confidential information is shared within a blockchain ecosystem.


🤝 What our project brings


❓Why

Our private file sharing system leverages Secret Network's encrypted transactions and secret contracts to enable truly confidential document sharing. Users can share files selectively with specific recipients, without publicly revealing document contents or the sharing activity. Secret Network's privacy-preserving technology allows building a file sharing solution that provides confidentiality and access control missing in public blockchains

🔑 Key Takeaway


📋 Use cases


💭 Technical proposal

Storage of the document

In order to store a document on the blockchain, we need to encrypt it. We can use a classical algorithm like AES-256-GCM for encryption. To use this algorithm, we need to generate and provide a key that can be used for both encryption and decryption of the document. This key will be unique per document.

The encrypted file can then be stored on the blockchain, as only the people who have access to the key can decrypt the document and read its content. There are multiple services available for storing the file. For small data information, we can think to store the content directly on Secret. However, for larger files, it can be interesting to use other services such as Arweave or IPFS. In our implementation, we will have two ways of storing the file information, first directly on secret for small data. The second implementation will be on Arweave. Of course, we will think about implementing a modular approach allowing other storage services depending of future use cases or constraints such as fees and document size limitations.

Secret Smart Contract - Storage of confidential information

On the Secret Network side, since everything is encrypted, we can store information confidentially. In our proposed use case, the file information can be broken down into three parts: the content, the encryption key, and the storage location (storage URL).

We can store the encryption key used to encrypt/decrypt the document and the link where the file is stored in the Secret smart contract. Since those information are stored privately, we can share it with other users. To control the sharing of the document, we need to control its access.

In Secret Network, we can use a Viewing Key or, eventually, a Signing Permits system to control user access.

Therefore, for storing and managing confidential information, we propose having a single Secret smart contract in our implementation. This contract will store confidential information dedicated to the file and manage its access.

Each information stored will be link to a specific key. This key will be require to access the information and it will be necessary to have it if you want to see the content of it. Given the key, we can retrieve the information on the smart contract. Here, we can get the storage URL and the encryption key stored by the owner. Also, each key, will have a metadata associated to the owner of the file. The owner will be the only one to update or revoke the information stored on chain.

Additionally, we can think about a read/write mechanism inside the smart contract where each item stored in our smart contract will be linked to a set of rights. We will have the owner, the people who can read and those who can write.

Proposition - PaaS - Create a new document

By using Secret Network as PaaS, a new user can create a request that will create a new document entry on the Smart Contract on Secret. We will call the Axelar bridge that will transfer the creation request to the Secret Smart Contract. This request will create a new entry in the Smart Contract, allowing the user to store the metadata information of the file.

When building the request, the user will generate a key for the encryption file and the associated link where the file is stored. Then, he will create a payload with those two information and he will use his private key from metamask to create a secret account. He can then build his transaction and send it using the Axelar bridge. For querying information on the Secret chain, the user can directly make a query request without having to pay fees.

When the creation request is done, the user will have in his possession a viewing key that allows him to see the information/metadata of the file. He can then prove to the Secret Smart contract that he has access to it and also have the possibility to update the information as he is the owner of the item.

Share the document with other

To share a document, a user can share a link with the document ID and the viewing key, which allows the user to retrieve the file information on the Secret Network contract.

When sharing a document, we can also think about rights that a given address could have, possibility to read or modify the content. This could be a possibility to have in our Secret smart contract.

Finally, in our proposed solution, we cannot control what the user will do with the document. If the user shares the key with others or if the user gains access to the document, decrypts it, and shares it with other people, we will not have access to it.

Decipher the document and get access to the IPFS link

To retrieve the information of the contract and gain access to the key, this can be queried directly on the Secret Network. Since it is a query, there will be no fees. We can use metamask information and SecretJS to retrieve data stored on the Secret chain.

In our proposed method, we do not want to add an additional wallet as Keplr because we believe the strength of using PaaS is to obfuscate all the blockchain interaction from the user perspective. They can rely on its security and enjoy a facilitated user experience and on-boarding.

Workflow Diagram - Create a new document

Here, we describe the workflow of a document creation. It will help us to better understanding the different steps and visualise it.

workflow-diagram


⚠️Constraints


🛫 Deliverable


🙏 Team

Team website : https://www.fiftywei.co/


🛣️ Roadmap

Milestone 1 - early january - beginning - Research and Design : 3.3K

Milestone 2 - end January- Core Development - The PoC : 8.5k

Milestone 3 - end February - Minimum Viable Product : 11.2k


💰Budget

Development: 21K