diff --git a/src/aead.js b/src/aead.js
new file mode 100644
index 0000000..8a6d8b1
--- /dev/null
+++ b/src/aead.js
@@ -0,0 +1,115 @@
+const kdf = require('./kdf');
+const keccak = require('./keccak');
+
+function splitIntoChunks(data) {
+    const chunks = [];
+    const chunkSize = 16;
+    for (let i = 0; i < data.length; i += chunkSize) {
+        const chunk = data.slice(i, i + chunkSize);
+        chunks.push(chunk);
+    }
+    return chunks;
+}
+
+class keccakAEAD {
+    constructor(iv, key) {
+        const input = kdf.concatUint8Arrays(iv, key);
+        this.state = keccak.SHAKE256(input, 32);
+    }
+
+    associated_data_processing(associated_data) {
+        const chunks = splitIntoChunks(associated_data);
+        let to_xor = null;
+        let c = null;
+        let r = null;
+        let input = null;
+        chunks.forEach((chunk) => {
+            to_xor = this.state.slice(0, 16);
+            c = this.state.slice(16, 32);
+            r = new Uint8Array(chunk.length);
+            for (let i = 0; i < chunk.length; i++) {
+                r[i] = chunk[i] ^ to_xor[i];
+            }
+            input = kdf.concatUint8Arrays(c, r);
+            this.state = keccak.SHAKE256(input, 32);
+        });
+    }
+
+    plaintext_processing(plaintext) {
+        const chunks = splitIntoChunks(plaintext);
+        let to_xor = null;
+        let c = null;
+        let r = null;
+        let input = null;
+        let cipherchunks = [];
+        chunks.forEach((chunk) => {
+            to_xor = this.state.slice(0, 16);
+            c = this.state.slice(16, 32);
+            r = new Uint8Array(chunk.length);
+            for (let i = 0; i < chunk.length; i++) {
+                r[i] = chunk[i] ^ to_xor[i];
+            }
+            cipherchunks.push(r);
+            input = kdf.concatUint8Arrays(c, r);
+            this.state = keccak.SHAKE256(input, 32);
+        });
+        return cipherchunks;
+    }
+
+    ciphertext_processing(ciphertext) {
+        const chunks = splitIntoChunks(ciphertext);
+        let to_xor = null;
+        let c = null;
+        let r = null;
+        let input = null;
+        let plaintextchunks = [];
+        chunks.forEach((chunk) => {
+            to_xor = this.state.slice(0, 16);
+            c = this.state.slice(16, 32);
+            r = new Uint8Array(chunk.length);
+            for (let i = 0; i < chunk.length; i++) {
+                r[i] = chunk[i] ^ to_xor[i];
+            }
+            plaintextchunks.push(r);
+            input = kdf.concatUint8Arrays(c, chunk);
+            this.state = keccak.SHAKE256(input, 32);
+        });
+        return plaintextchunks;
+    }
+
+    finalize(key) {
+        const output = keccak.SHAKE256(this.state, 32);
+        let to_xor = output.slice(16, 32);
+        let tag = new Uint8Array(key.length);
+        for (let i = 0; i < key.length; i++) {
+            tag[i] = key[i] ^ to_xor[i];
+        }
+        return tag;
+    }
+
+    static encrypt(key, plaintext, iv, associated_data) {
+        let sponge = new keccakAEAD(iv, key);
+        sponge.associated_data_processing(associated_data);
+        let cipherChunks = sponge.plaintext_processing(plaintext);
+        let ciphertext = kdf.concatUint8Arrays(...cipherChunks);
+        let tag = sponge.finalize(key);
+        return {
+            cipher: ciphertext,
+            tag: tag
+        };
+    }
+
+    static decrypt(key, ciphertext, iv, associated_data) {
+        let sponge = new keccakAEAD(iv, key);
+        sponge.associated_data_processing(associated_data);
+        let plaintextChunks = sponge.ciphertext_processing(ciphertext);
+        let plaintext = kdf.concatUint8Arrays(...plaintextChunks);
+        let tag = sponge.finalize(key);
+        return {
+            plaintext: plaintext,
+            tag: tag
+        };
+    }
+}
+
+module.exports = { keccakAEAD };
diff --git a/src/kdf.js b/src/kdf.js
index 41f9c91..24e381b 100644
--- a/src/kdf.js
+++ b/src/kdf.js
@@ -37,4 +37,4 @@ class keccakKDF {
 
 }
 
-module.exports = { keccakKDF };
+module.exports = { keccakKDF, concatUint8Arrays };
diff --git a/tests/aead.test.js b/tests/aead.test.js
new file mode 100644
index 0000000..9df5af7
--- /dev/null
+++ b/tests/aead.test.js
@@ -0,0 +1,25 @@
+const aead = require('../src/aead');
+const crypto = require('crypto');
+
+function generateRandomUint8Array(length = 16) {
+  const randomArray = new Uint8Array(length);
+  crypto.getRandomValues(randomArray);
+  return randomArray;
+}
+
+describe('aead.js functions', () => {
+
+    it('encrypt and decrypt', () => {
+        let msg = generateRandomUint8Array(28);
+        console.log(msg);
+        let ad = generateRandomUint8Array(12);
+        let iv = generateRandomUint8Array();
+        let key = generateRandomUint8Array();
+        let result = aead.keccakAEAD.encrypt(key, msg, iv, ad);
+        console.log(result.tag);
+        console.log(result.cipher);
+        let result2 = aead.keccakAEAD.decrypt(key, result.cipher, iv, ad);
+        console.log(result2.tag);
+        console.log(result2.plaintext);
+    });
+});