src/controllers/NostrController.ts

@@ -378,6 +378,54 @@ export class NostrController extends EventEmitter {
     throw new Error('Login method is undefined')
   }
 
+  nip04Decrypt = async (sender: string, content: string) => {
+    const loginMethod = (store.getState().auth as AuthState).loginMethod
+
+    if (loginMethod === LoginMethods.extension) {
+      const nostr = this.getNostrObject()
+
+      if (!nostr.nip04) {
+        throw new Error(
+          `Your nostr extension does not support nip04 encryption & decryption`
+        )
+      }
+
+      const decrypted = await nostr.nip04.decrypt(sender, content)
+      return decrypted
+    }
+
+    if (loginMethod === LoginMethods.privateKey) {
+      const keys = (store.getState().auth as AuthState).keyPair
+
+      if (!keys) {
+        throw new Error(
+          `Login method is ${LoginMethods.privateKey} but private & public key pair is not found.`
+        )
+      }
+
+      const { private: nsec } = keys
+      const privateKey = nip19.decode(nsec).data as Uint8Array
+
+      const decrypted = await nip04.decrypt(privateKey, sender, content)
+      return decrypted
+    }
+
+    if (loginMethod === LoginMethods.nsecBunker) {
+      const user = new NDKUser({ pubkey: sender })
+
+      this.remoteSigner?.on('authUrl', (authUrl) => {
+        this.emit('nsecbunker-auth', authUrl)
+      })
+
+      if (!this.remoteSigner) throw new Error('Remote signer is undefined.')
+      const decrypted = await this.remoteSigner.decrypt(user, content)
+
+      return decrypted
+    }
+
+    throw new Error('Login method is undefined')
+  }
+
   /**
    * Function will capture the public key from the nostr extension or if no extension present
    * function wil capture the public key from the local storage

src/pages/create/index.tsx

@@ -33,6 +33,7 @@ import { Meta, ProfileMetadata, User, UserRole } from '../../types'
 import {
   encryptArrayBuffer,
   generateEncryptionKey,
+  generateKeysFile,
   getHash,
   hexToNpub,
   isOnline,
@@ -49,15 +50,12 @@ import { HTML5Backend } from 'react-dnd-html5-backend'
 import type { Identifier, XYCoord } from 'dnd-core'
 import { useDrag, useDrop } from 'react-dnd'
 import saveAs from 'file-saver'
-import CopyModal from '../../components/copyModal'
 import { Event, kinds } from 'nostr-tools'
 
 export const CreatePage = () => {
   const navigate = useNavigate()
   const [isLoading, setIsLoading] = useState(false)
   const [loadingSpinnerDesc, setLoadingSpinnerDesc] = useState('')
-  const [openCopyModal, setOpenCopyModel] = useState(false)
-  const [textToCopy, setTextToCopy] = useState('')
 
   const [authUrl, setAuthUrl] = useState<string>()
 
@@ -374,26 +372,68 @@ export const CreatePage = () => {
     encryptionKey: string
   ): Promise<ArrayBuffer> => {
     setLoadingSpinnerDesc('Encrypting zip file')
-    return encryptArrayBuffer(arraybuffer, encryptionKey).finally(() =>
-      setIsLoading(false)
+    return encryptArrayBuffer(arraybuffer, encryptionKey)
+  }
+
+  // create final zip file
+  const createFinalZipFile = async (
+    encryptedArrayBuffer: ArrayBuffer,
+    encryptionKey: string
+  ): Promise<File | null> => {
+    // Get the current timestamp in seconds
+    const unixNow = Math.floor(Date.now() / 1000)
+    const blob = new Blob([encryptedArrayBuffer])
+    // Create a File object with the Blob data
+    const file = new File([blob], `compressed.sigit`, {
+      type: 'application/sigit'
+    })
+
+    const firstSigner = users.filter((user) => user.role === UserRole.signer)[0]
+
+    const keysFileContent = await generateKeysFile(
+      [firstSigner.pubkey],
+      encryptionKey
     )
+    if (!keysFileContent) return null
+
+    const zip = new JSZip()
+    zip.file(`compressed.sigit`, file)
+    zip.file('keys.json', keysFileContent)
+
+    const arraybuffer = await zip
+      .generateAsync({
+        type: 'arraybuffer',
+        compression: 'DEFLATE',
+        compressionOptions: { level: 6 }
+      })
+      .catch(handleZipError)
+
+    if (!arraybuffer) return null
+
+    const finalZipFile = new File(
+      [new Blob([arraybuffer])],
+      `${unixNow}.sigit.zip`,
+      {
+        type: 'application/zip'
+      }
+    )
+
+    return finalZipFile
   }
 
   // Handle file upload and further actions based on online/offline status
-  const handleFileUpload = async (blob: Blob, encryptionKey: string) => {
+  const handleFileUpload = async (file: File, arrayBuffer: ArrayBuffer) => {
     if (await isOnline()) {
-      const fileUrl = await uploadFile(blob)
+      const fileUrl = await uploadFile(file)
 
       if (!fileUrl) return
 
-      await sendDMs(fileUrl, encryptionKey)
+      await sendDMs(fileUrl)
       setIsLoading(false)
 
-      navigate(
-        `${appPrivateRoutes.sign}?file=${encodeURIComponent(fileUrl)}&key=${encodeURIComponent(encryptionKey)}`
-      )
+      navigate(appPrivateRoutes.sign, { state: { arrayBuffer } })
     } else {
-      handleOffline(blob, encryptionKey)
+      handleOffline(file, arrayBuffer)
     }
   }
 
@@ -406,11 +446,11 @@ export const CreatePage = () => {
   }
 
   // Upload the file to the storage and send DMs to signers/viewers
-  const uploadFile = async (blob: Blob): Promise<string | null> => {
+  const uploadFile = async (file: File): Promise<string | null> => {
     setIsLoading(true)
     setLoadingSpinnerDesc('Uploading zip file to file storage.')
 
-    const fileUrl = await uploadToFileStorage(blob, nostrController)
+    const fileUrl = await uploadToFileStorage(file, nostrController)
       .then((url) => {
         toast.success('zip file uploaded to file storage')
         return url
@@ -420,8 +460,8 @@ export const CreatePage = () => {
     return fileUrl
   }
 
-  // Send DMs to signers and viewers with the file URL and encryption key
-  const sendDMs = async (fileUrl: string, encryptionKey: string) => {
+  // Send DMs to signers and viewers with the file URL
+  const sendDMs = async (fileUrl: string) => {
     setLoadingSpinnerDesc('Sending DM to signers/viewers')
 
     const signers = users.filter((user) => user.role === UserRole.signer)
@@ -430,7 +470,6 @@ export const CreatePage = () => {
     if (signers.length > 0) {
       await sendDM(
         fileUrl,
-        encryptionKey,
         signers[0].pubkey,
         nostrController,
         true,
@@ -438,34 +477,15 @@ export const CreatePage = () => {
       )
     } else {
       for (const viewer of viewers) {
-        await sendDM(
-          fileUrl,
-          encryptionKey,
-          viewer.pubkey,
-          nostrController,
-          false,
-          setAuthUrl
-        )
+        await sendDM(fileUrl, viewer.pubkey, nostrController, false, setAuthUrl)
       }
     }
   }
 
   // Manage offline scenarios for signing or viewing the file
-  const handleOffline = (blob: Blob, encryptionKey: string) => {
-    const signers = users.filter((user) => user.role === UserRole.signer)
-
-    if (signers[0] && signers[0].pubkey === usersPubkey) {
-      // Create a File object with the Blob data for offline signing
-      const file = new File([blob], `compressed.sigit`, {
-        type: 'application/sigit'
-      })
-      navigate(appPrivateRoutes.sign, { state: { file, encryptionKey } })
-    } else {
-      // Save the file and show encryption key for offline viewing
-      saveAs(blob, 'request.sigit')
-      setTextToCopy(encryptionKey)
-      setOpenCopyModel(true)
-    }
+  const handleOffline = (file: File, arrayBuffer: ArrayBuffer) => {
+    saveAs(file, 'request.sigit.zip')
+    navigate(appPrivateRoutes.sign, { state: { arrayBuffer } })
   }
 
   const handleCreate = async () => {
@@ -497,9 +517,15 @@ export const CreatePage = () => {
       arraybuffer,
       encryptionKey
     )
-    const blob = new Blob([encryptedArrayBuffer])
 
-    return await handleFileUpload(blob, encryptionKey)
+    const finalZipFile = await createFinalZipFile(
+      encryptedArrayBuffer,
+      encryptionKey
+    )
+
+    if (!finalZipFile) return
+
+    return await handleFileUpload(finalZipFile, arraybuffer)
   }
 
   if (authUrl) {
@@ -596,15 +622,6 @@ export const CreatePage = () => {
           </Button>
         </Box>
       </Box>
-      <CopyModal
-        open={openCopyModal}
-        handleClose={() => {
-          setOpenCopyModel(false)
-          navigate(appPrivateRoutes.sign)
-        }}
-        title="Decryption key for Sigit file"
-        textToCopy={textToCopy}
-      />
     </>
   )
 }

src/pages/sign/index.tsx

@@ -10,7 +10,6 @@ import {
   TableCell,
   TableHead,
   TableRow,
-  TextField,
   Tooltip,
   Typography,
   useTheme
@@ -52,7 +51,8 @@ import {
   shorten,
   signEventForMetaFile,
   uploadToFileStorage,
-  isOnline
+  isOnline,
+  generateKeysFile
 } from '../../utils'
 import styles from './style.module.scss'
 import {
@@ -71,14 +71,13 @@ enum SignedStatus {
 export const SignPage = () => {
   const navigate = useNavigate()
   const location = useLocation()
-  const { file, encryptionKey: encKey } = location.state || {}
+  const { arrayBuffer: decryptedArrayBuffer } = location.state || {}
 
-  const [searchParams, setSearchParams] = useSearchParams()
+  const [searchParams] = useSearchParams()
 
   const [displayInput, setDisplayInput] = useState(false)
 
   const [selectedFile, setSelectedFile] = useState<File | null>(null)
-  const [encryptionKey, setEncryptionKey] = useState('')
 
   const [zip, setZip] = useState<JSZip>()
 
@@ -194,9 +193,8 @@ export const SignPage = () => {
 
   useEffect(() => {
     const fileUrl = searchParams.get('file')
-    const key = searchParams.get('key')
 
-    if (fileUrl && key) {
+    if (fileUrl) {
       setIsLoading(true)
       setLoadingSpinnerDesc('Fetching file from file server')
 
@@ -208,7 +206,7 @@ export const SignPage = () => {
           const fileName = fileUrl.split('/').pop()
           const file = new File([res.data], fileName!)
 
-          decrypt(file, decodeURIComponent(key)).then((arrayBuffer) => {
+          decrypt(file).then((arrayBuffer) => {
             if (arrayBuffer) handleDecryptedArrayBuffer(arrayBuffer)
           })
         })
@@ -221,40 +219,109 @@ export const SignPage = () => {
         .finally(() => {
           setIsLoading(false)
         })
-    } else if (file && encKey) {
-      decrypt(file, decodeURIComponent(encKey))
-        .then((arrayBuffer) => {
-          if (arrayBuffer) handleDecryptedArrayBuffer(arrayBuffer)
-        })
-        .catch((err) => {
-          console.error(`error occurred in decryption`, err)
-          toast.error(err.message || `error occurred in decryption`)
-        })
-        .finally(() => {
-          setIsLoading(false)
-        })
+    } else if (decryptedArrayBuffer) {
+      handleDecryptedArrayBuffer(decryptedArrayBuffer).finally(() =>
+        setIsLoading(false)
+      )
     } else {
       setIsLoading(false)
       setDisplayInput(true)
     }
-  }, [searchParams, file, encKey])
+  }, [searchParams, decryptedArrayBuffer])
 
-  const decrypt = async (file: File, key: string) => {
+  const parseKeysJson = async (zip: JSZip) => {
+    const keysFileContent = await readContentOfZipEntry(
+      zip,
+      'keys.json',
+      'string'
+    )
+
+    if (!keysFileContent) return null
+
+    const parsedJSON = await parseJson<{ sender: string; keys: string[] }>(
+      keysFileContent
+    ).catch((err) => {
+      console.log(`Error parsing content of keys.json:`, err)
+      toast.error(err.message || `Error parsing content of keys.json`)
+      return null
+    })
+
+    return parsedJSON
+  }
+
+  const decrypt = async (file: File) => {
     setLoadingSpinnerDesc('Decrypting file')
 
-    const encryptedArrayBuffer = await file.arrayBuffer()
+    const zip = await JSZip.loadAsync(file).catch((err) => {
+      console.log('err in loading zip file :>> ', err)
+      toast.error(err.message || 'An error occurred in loading zip file.')
+      return null
+    })
+    if (!zip) return
 
-    const arrayBuffer = await decryptArrayBuffer(encryptedArrayBuffer, key)
-      .catch((err) => {
-        console.log('err in decryption:>> ', err)
-        toast.error(err.message || 'An error occurred in decrypting file.')
-        return null
-      })
-      .finally(() => {
-        setIsLoading(false)
+    const parsedKeysJson = await parseKeysJson(zip)
+    if (!parsedKeysJson) return
+
+    const encryptedArrayBuffer = await readContentOfZipEntry(
+      zip,
+      'compressed.sigit',
+      'arraybuffer'
+    )
+
+    if (!encryptedArrayBuffer) return
+
+    const { keys, sender } = parsedKeysJson
+
+    for (const key of keys) {
+      // Set up event listener for authentication event
+      nostrController.on('nsecbunker-auth', (url) => {
+        setAuthUrl(url)
       })
 
-    return arrayBuffer
+      // Set up timeout promise to handle encryption timeout
+      const timeoutPromise = new Promise<never>((_, reject) => {
+        setTimeout(() => {
+          reject(new Error('Timeout occurred'))
+        }, 60000) // Timeout duration = 60 seconds
+      })
+
+      // decrypt the encryptionKey, with timeout
+      const encryptionKey = await Promise.race([
+        nostrController.nip04Decrypt(sender, key),
+        timeoutPromise
+      ])
+        .then((res) => {
+          return res
+        })
+        .catch((err) => {
+          console.log('err :>> ', err)
+          return null
+        })
+        .finally(() => {
+          setAuthUrl(undefined) // Clear authentication URL
+        })
+
+      console.log('encryptionKey :>> ', encryptionKey)
+
+      // Return if encryption failed
+      if (!encryptionKey) continue
+
+      const arrayBuffer = await decryptArrayBuffer(
+        encryptedArrayBuffer,
+        encryptionKey
+      )
+        .catch((err) => {
+          console.log('err in decryption:>> ', err)
+          return null
+        })
+        .finally(() => {
+          setIsLoading(false)
+        })
+
+      if (arrayBuffer) return arrayBuffer
+    }
+
+    return null
   }
 
   const handleDecryptedArrayBuffer = async (arrayBuffer: ArrayBuffer) => {
@@ -348,13 +415,10 @@ export const SignPage = () => {
   }
 
   const handleDecrypt = async () => {
-    if (!selectedFile || !encryptionKey) return
+    if (!selectedFile) return
 
     setIsLoading(true)
-    const arrayBuffer = await decrypt(
-      selectedFile,
-      decodeURIComponent(encryptionKey)
-    )
+    const arrayBuffer = await decrypt(selectedFile)
 
     if (!arrayBuffer) return
 
@@ -407,13 +471,15 @@ export const SignPage = () => {
     setLoadingSpinnerDesc('Encrypting zip file')
     const encryptedArrayBuffer = await encryptArrayBuffer(arrayBuffer, key)
 
-    const blob = new Blob([encryptedArrayBuffer])
+    const finalZipFile = await createFinalZipFile(encryptedArrayBuffer, key)
+
+    if (!finalZipFile) return
 
     if (await isOnline()) {
-      await handleOnlineFlow(blob, key)
-    } else {
-      handleDecryptedArrayBuffer(arrayBuffer).finally(() => setIsLoading(false))
+      await handleOnlineFlow(finalZipFile)
     }
+
+    handleDecryptedArrayBuffer(arrayBuffer).finally(() => setIsLoading(false))
   }
 
   // Read the content of the hashes.json file
@@ -491,32 +557,101 @@ export const SignPage = () => {
       })
   }
 
+  // create final zip file
+  const createFinalZipFile = async (
+    encryptedArrayBuffer: ArrayBuffer,
+    encryptionKey: string
+  ): Promise<File | null> => {
+    // Get the current timestamp in seconds
+    const unixNow = Math.floor(Date.now() / 1000)
+    const blob = new Blob([encryptedArrayBuffer])
+    // Create a File object with the Blob data
+    const file = new File([blob], `compressed.sigit`, {
+      type: 'application/sigit'
+    })
+
+    const isLastSigner = checkIsLastSigner(signers)
+
+    const userSet = new Set<string>()
+
+    if (isLastSigner) {
+      if (submittedBy) {
+        userSet.add(submittedBy)
+      }
+
+      signers.forEach((signer) => {
+        userSet.add(npubToHex(signer)!)
+      })
+
+      viewers.forEach((viewer) => {
+        userSet.add(npubToHex(viewer)!)
+      })
+    } else {
+      const usersNpub = hexToNpub(usersPubkey!)
+      const signerIndex = signers.indexOf(usersNpub)
+      const nextSigner = signers[signerIndex + 1]
+      userSet.add(npubToHex(nextSigner)!)
+    }
+
+    const keysFileContent = await generateKeysFile(
+      Array.from(userSet),
+      encryptionKey
+    )
+    if (!keysFileContent) return null
+
+    const zip = new JSZip()
+    zip.file(`compressed.sigit`, file)
+    zip.file('keys.json', keysFileContent)
+
+    const arraybuffer = await zip
+      .generateAsync({
+        type: 'arraybuffer',
+        compression: 'DEFLATE',
+        compressionOptions: { level: 6 }
+      })
+      .catch(handleZipError)
+
+    if (!arraybuffer) return null
+
+    const finalZipFile = new File(
+      [new Blob([arraybuffer])],
+      `${unixNow}.sigit.zip`,
+      {
+        type: 'application/zip'
+      }
+    )
+
+    return finalZipFile
+  }
+
+  // Handle errors during zip file generation
+  const handleZipError = (err: any) => {
+    console.log('Error in zip:>> ', err)
+    setIsLoading(false)
+    toast.error(err.message || 'Error occurred in generating zip file')
+    return null
+  }
+
   // Handle the online flow: upload file and send DMs
-  const handleOnlineFlow = async (blob: Blob, key: string) => {
-    const fileUrl = await uploadZipFile(blob)
+  const handleOnlineFlow = async (file: File) => {
+    const fileUrl = await uploadZipFile(file)
     if (!fileUrl) return
 
     const isLastSigner = checkIsLastSigner(signers)
 
     if (isLastSigner) {
-      await sendDMToAllUsers(fileUrl, key)
+      await sendDMToAllUsers(fileUrl)
     } else {
-      await sendDMToNextSigner(fileUrl, key)
+      await sendDMToNextSigner(fileUrl)
     }
 
     setIsLoading(false)
-
-    // Update search params with updated file URL and encryption key
-    setSearchParams({
-      file: fileUrl,
-      key: key
-    })
   }
 
   // Upload the zip file to file storage
-  const uploadZipFile = async (blob: Blob): Promise<string | null> => {
+  const uploadZipFile = async (file: File): Promise<string | null> => {
     setLoadingSpinnerDesc('Uploading zip file to file storage.')
-    const fileUrl = await uploadToFileStorage(blob, nostrController)
+    const fileUrl = await uploadToFileStorage(file, nostrController)
       .then((url) => {
         toast.success('Zip file uploaded to file storage')
         return url
@@ -540,7 +675,7 @@ export const SignPage = () => {
   }
 
   // Send DM to all users (signers and viewers)
-  const sendDMToAllUsers = async (fileUrl: string, key: string) => {
+  const sendDMToAllUsers = async (fileUrl: string) => {
     const userSet = new Set<`npub1${string}`>()
 
     if (submittedBy) {
@@ -560,7 +695,6 @@ export const SignPage = () => {
     for (const user of users) {
       await sendDM(
         fileUrl,
-        key,
         npubToHex(user)!,
         nostrController,
         false,
@@ -570,13 +704,12 @@ export const SignPage = () => {
   }
 
   // Send DM to the next signer
-  const sendDMToNextSigner = async (fileUrl: string, key: string) => {
+  const sendDMToNextSigner = async (fileUrl: string) => {
     const usersNpub = hexToNpub(usersPubkey!)
     const signerIndex = signers.indexOf(usersNpub)
     const nextSigner = signers[signerIndex + 1]
     await sendDM(
       fileUrl,
-      key,
       npubToHex(nextSigner)!,
       nostrController,
       true,
@@ -771,18 +904,9 @@ export const SignPage = () => {
                 value={selectedFile}
                 onChange={(value) => setSelectedFile(value)}
               />
-
-              {selectedFile && (
-                <TextField
-                  label="Encryption Key"
-                  variant="outlined"
-                  value={encryptionKey}
-                  onChange={(e) => setEncryptionKey(e.target.value)}
-                />
-              )}
             </Box>
 
-            {selectedFile && encryptionKey && (
+            {selectedFile && (
               <Box sx={{ mt: 2, display: 'flex', justifyContent: 'center' }}>
                 <Button onClick={handleDecrypt} variant="contained">
                   Decrypt

src/utils/misc.ts

@@ -1,5 +1,10 @@
 import axios from 'axios'
-import { EventTemplate } from 'nostr-tools'
+import {
+  EventTemplate,
+  generateSecretKey,
+  getPublicKey,
+  nip04
+} from 'nostr-tools'
 import { MetadataController, NostrController } from '../controllers'
 import { toast } from 'react-toastify'
 import { appPrivateRoutes } from '../routes'
@@ -11,17 +16,12 @@ import { appPrivateRoutes } from '../routes'
  * @returns The URL of the uploaded file.
  */
 export const uploadToFileStorage = async (
-  blob: Blob,
+  file: File,
   nostrController: NostrController
 ) => {
   // Get the current timestamp in seconds
   const unixNow = Math.floor(Date.now() / 1000)
 
-  // Create a File object with the Blob data
-  const file = new File([blob], `compressed-${unixNow}.sigit`, {
-    type: 'application/sigit'
-  })
-
   // Define event metadata for authorization
   const event: EventTemplate = {
     kind: 24242,
@@ -56,7 +56,6 @@ export const uploadToFileStorage = async (
 /**
  * Sends a Direct Message (DM) to a recipient, encrypting the content and handling authentication.
  * @param fileUrl The URL of the encrypted zip file to be included in the DM.
- * @param encryptionKey The encryption key used to decrypt the zip file to be included in the DM.
  * @param pubkey The public key of the recipient.
  * @param nostrController The NostrController instance for handling authentication and encryption.
  * @param isSigner Boolean indicating whether the recipient is a signer or viewer.
@@ -64,7 +63,6 @@ export const uploadToFileStorage = async (
  */
 export const sendDM = async (
   fileUrl: string,
-  encryptionKey: string,
   pubkey: string,
   nostrController: NostrController,
   isSigner: boolean,
@@ -77,9 +75,7 @@ export const sendDM = async (
 
   const decryptionUrl = `${window.location.origin}/#${
     appPrivateRoutes.sign
-  }?file=${encodeURIComponent(fileUrl)}&key=${encodeURIComponent(
-    encryptionKey
-  )}`
+  }?file=${encodeURIComponent(fileUrl)}`
 
   const content = `${initialLine}\n\n${decryptionUrl}`
 
@@ -205,3 +201,52 @@ export const signEventForMetaFile = async (
 
   return signedEvent // Return the signed event
 }
+
+/**
+ * Generates the content for keys.json file.
+ *
+ * @param users - An array of public keys.
+ * @param key - The key that will be encrypted for each user.
+ * @returns A promise that resolves to a JSON string containing the sender's public key and encrypted keys, or null if an error occurs.
+ */
+export const generateKeysFile = async (
+  users: string[],
+  key: string
+): Promise<string | null> => {
+  // Generate a random private key to act as the sender
+  const privateKey = generateSecretKey()
+
+  // Calculate the required length to be a multiple of 10
+  const requiredLength = Math.ceil(users.length / 10) * 10
+  const additionalKeysCount = requiredLength - users.length
+
+  if (additionalKeysCount > 0) {
+    // generate random public keys to make the keys array multiple of 10
+    const additionalPubkeys = Array.from({ length: additionalKeysCount }, () =>
+      getPublicKey(generateSecretKey())
+    )
+
+    users.push(...additionalPubkeys)
+  }
+
+  // Encrypt the key for each user's public key
+  const promises = users.map((pubkey) => nip04.encrypt(privateKey, pubkey, key))
+
+  // Wait for all encryption promises to resolve
+  const keys = await Promise.all(promises).catch((err) => {
+    console.log('Error while generating keys :>> ', err)
+    toast.error(err.message || 'An error occurred while generating key')
+    return null
+  })
+
+  // If any encryption promise failed, return null
+  if (!keys) return null
+
+  try {
+    // Return a JSON string containing the sender's public key and encrypted keys
+    return JSON.stringify({ sender: getPublicKey(privateKey), keys })
+  } catch (error) {
+    // Return null if an error occurs during JSON stringification
+    return null
+  }
+}