Creé un ejemplo de TypeScript a partir del ejemplo de MDN tan textualmente como pude para ilustrar. Cifra y descifra perfectamente. Me acabo de dar cuenta de que, para que Decryption funcione, requiere el mismo init_vector del cifrado. ¿No se supone que init_vector es un nonce?

¿Cómo va a saber la persona que recibe el mensaje cuál es el init_vector que he usado para el cifrado si el descifrado es un proceso separado realizado en un lugar y momento diferentes?

 const message_plain: string = "Hello World!"; const password_plain: string = "letmein"; // AES-GCM - ENCRYPTION const pbkdf2_salt: Uint8Array = crypto.getRandomValues(new Uint8Array(16)); // 128 bits const pbkdf2_iterations: number = 100000; const init_vector: Uint8Array = crypto.getRandomValues(new Uint8Array(12)); // 96 bits const utf8_encoder: TextEncoder = new TextEncoder(); const message_bytes: Uint8Array = utf8_encoder.encode(message_plain); const password_bytes: Uint8Array = utf8_encoder.encode(password_plain); const crypto_key_material: CryptoKey = await crypto.subtle.importKey( "raw", password_bytes, { name: "PBKDF2" }, false, ["deriveBits", "deriveKey"], ); const crypto_key_derived: CryptoKey = await crypto.subtle.deriveKey( { "name": "PBKDF2", salt: pbkdf2_salt, "iterations": pbkdf2_iterations, "hash": "SHA-256", }, crypto_key_material, { "name": "AES-GCM", "length": 256 }, true, ["encrypt", "decrypt"], ); const message_encrypted: ArrayBuffer = await crypto.subtle.encrypt( { name: "AES-GCM", iv: init_vector }, crypto_key_derived, message_bytes, ); const message_encrypted_bytes: Uint8Array = new Uint8Array(message_encrypted); console.log( `[${message_encrypted.byteLength} bytes total] -> ${message_encrypted_bytes}`, ); // AES-GCM - DECRYPTION const utf8Decoder: TextDecoder = new TextDecoder(); try { const message_decrypted: ArrayBuffer = await crypto.subtle.decrypt( { name: "AES-GCM", iv: init_vector }, crypto_key_derived, message_encrypted, ); const message_decrypted_bytes: Uint8Array = new Uint8Array(message_decrypted); console.log(utf8Decoder.decode(message_decrypted_bytes)); } catch (e) { console.log("*** Decryption error ***"); }