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vetKeys example

Advanced
Encryption

This example provides a canister (src/chainkey_testing_canister) that demonstrates how the proposed vetKD system API can be used to encrypt, transfer, and decrypt a file sent to an Ethereum address.

The GitHub repo for this example is a public template, and there is a live demo available: https://h62xu-2iaaa-aaaal-qshoq-cai.icp0.io/

It uses ic-siwe and ic-siwe-js to facilitate signing in with Ethereum, sending a file to an Ethereum address, and using the recipient's address to to identify the IBE scheme used to generate a public key for the recipient.

Other examples available are:

Encrypt and store a file​

Step 1: Retrieve recipient's public key​

First, identify the Ethereum address of the recipient you'd like to send a file to. Then, define a vetkd_public_key method that will retrieve the recipient's public key using their Ethereum address to identify the IBE scheme that generates the public key. This method will call the chainkey_testing_canister:

src/backend/src/vetkd/controller/vetkd_public_key.rs
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This example uses a local test vetKeys canister. When the feature is available, this should be replaced with the actual vetKeys API.

Step 2: Encrypt a file in the frontend​

Next, define a request in the application's frontend that uses the recipient's public key and the vetkd.IBECiphertext.encrypt method from the ic-vetkd-utils package. This request will take the file uploaded by the user and encrypt it.

src/frontend/src/transfer/hooks/useTransferCreate.tsx
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Step 3: Store the encrypted file in the backend​

In the backend canister, create a transfer_create method that verifies the frontend request's from and to parameters, then stores the encrypted file:

src/backend/src/transfer/controller/transfer_create.rs
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Receive and decrypt a file​

Step 1: Obtain a list of available encrypted file transfers​

The file has now been encrypted with the intended recipient's Ethereum address and corresponding private key. In order for the recipient to receive the file, they must login to the application with their Ethereum address. The frontend will call the backend's transfer_list method and receive the application's existing file transfers.

src/backend/src/transfer/controller/transfer_list.rs
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Step 2: Obtain the recipient's private key​

Then the backend obtains the encrypted private key of the user's Ethereum address in a similar manner to how it obtained the public key to encrypt the file:

src/backend/src/vetkd/controller/vetkd_encrypted_key.rs
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Step 3: Decrypt the private key and file​

Finally, the frontend decrypts the private key, uses it to decrypt the file, and returns the file to the user:

src/frontend/src/transfer/hooks/useTransferGet.tsx
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