🤝 Share Encrypted Files

Once you've uploaded an encrypted file to Walrus, you can share access with other SUI addresses by adding them to the file's allowlist.

UI

Sharing an Encrypted File

Follow these steps from the Lighthouse Files Dapp:

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Step 1: Locate Your Encrypted File

From your files dashboard, find the encrypted file you want to share. Encrypted files are marked with a lock icon.

Click on the file to open its details view.

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Step 2: Open the Share Panel

In the file details view, click the Share button. This opens the share panel where you can manage who has access to your encrypted file.

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Step 3: Add a Wallet Address

Enter the Sui wallet address of the person you want to share the file with. This is the address that will be granted permission to decrypt the file.

The address must be a valid Sui wallet address. Lighthouse will validate the format before proceeding.

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Step 4: Sign the Transaction

After entering the wallet address, your Sui wallet will prompt you to sign a transaction. This transaction:

• Calls the add_user function on the file's FileAllowlist object
• Adds the specified wallet address to the allowlist
• Updates the on-chain access control for the encrypted file

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Step 5: Confirmation

Once the transaction is confirmed on-chain, the recipient's wallet address is added to the allowlist. They can now:

• View the encrypted file in their own dashboard (if they have the CID)
• Prove ownership and decrypt the file using SEAL
• Access the file contents on their device

The shared wallet will appear in your file's access list, confirming the share was successful.

Sharing Multiple Files

You can repeat this process to share the file with multiple wallet addresses. Each address is added independently to the allowlist.

Code

Sharing an Encrypted File (Code)

Sharing an encrypted file adds a wallet address to the FileAllowlist object, granting them permission to decrypt the file.

The share flow requires:

• The FileAllowlist object ID for the encrypted file
• The Cap object ID owned by the file owner (proves authority over the allowlist)
• The recipient's Sui wallet address
• The original uploader's keypair (must own the Cap)

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Share Function

import { Transaction } from "@mysten/sui/transactions";

const LATEST_PACKAGE_ID =
  "0x89815d9feb1e8e526bed4b3c7ad35056a6abf692f293103f435d909180cecb7d";

export async function shareFile(
  keypair: Keypair,
  fileAllowlistId: string,
  capId: string,
  recipientAddress: string,
) {
  const tx = new Transaction();

  tx.moveCall({
    target: `${LATEST_PACKAGE_ID}::allowlist::add_user`,
    arguments: [
      tx.object(fileAllowlistId),
      tx.object(capId),
      tx.pure.address(recipientAddress),
    ],
  });

  const result = await suiClient.signAndExecuteTransaction({
    signer: keypair,
    transaction: tx,
  });

  await suiClient.waitForTransaction({
    digest: result.digest,
  });

  return result.digest;
}

Where:

• keypair is the keypair of the file owner (who holds the Cap)
• fileAllowlistId is the object ID of the FileAllowlist created during encryption
• capId is the object ID of the Cap returned when the allowlist was created — required to authorize add_user
• recipientAddress is the Sui wallet address to grant access to

Recipient Requirements

The recipient needs:

• The CID of the encrypted file on Walrus
• The FileAllowlist object ID
• The same SEAL configuration (package IDs, key server object IDs)