encryption_one_to_many

encryption_one_to_many.js

// https://jsbin.com/rasuwilojo/6/edit?js,console

(async () => {
  
  /////////////////////////////////////////////////////////////////
  // Instead of logging in with actual users, we are 
  // going to generate SEA pairs which is basically the same thing
  /////////////////////////////////////////////////////////////////
  
  // User 1 encrypts one message
  const user1 = await SEA.pair();
  
  const plainMessage = 'Hello, how are you?';
  const encryptionKey = 'this is my encryption key which is a normal string';
  const encryptedMessage = await SEA.encrypt(plainMessage, encryptionKey);
  
  // User 2, 3 and 4 will receive the message and decrypt it
  const user2 = await SEA.pair();
  const user3 = await SEA.pair();
  const user4 = await SEA.pair();
  
  // Each user gets an encrypted encryption key. If you print them, they all different
  const encryptedEncryptionKeyUser2 = await SEA.encrypt(encryptionKey, await SEA.secret(user2.epub, user1));
  const encryptedEncryptionKeyUser3 = await SEA.encrypt(encryptionKey, await SEA.secret(user3.epub, user1));
  const encryptedEncryptionKeyUser4 = await SEA.encrypt(encryptionKey, await SEA.secret(user4.epub, user1));
  
 
  // Each user decrypts his own encrypted encryption key
  // These three decrypted encryptions keys that we get are all the same
  const decryptedEncryptionKeyUser2 = await SEA.decrypt(
    encryptedEncryptionKeyUser2, 
    await SEA.secret(user1.epub, user2)
  );
  const decryptedEncryptionKeyUser3 = await SEA.decrypt(
    encryptedEncryptionKeyUser3, 
    await SEA.secret(user1.epub, user3)
  );
  const decryptedEncryptionKeyUser4 = await SEA.decrypt(
    encryptedEncryptionKeyUser4, 
    await SEA.secret(user1.epub, user4)
  );
  
  // Each user decrypts the encrypted message using the decrypted encryption key
  const decryptedMessageUser2 = await SEA.decrypt(encryptedMessage, decryptedEncryptionKeyUser2);
  const decryptedMessageUser3 = await SEA.decrypt(encryptedMessage, decryptedEncryptionKeyUser3);
  const decryptedMessageUser4 = await SEA.decrypt(encryptedMessage, decryptedEncryptionKeyUser4);
  
})();