diff --git a/.ideas/future_improvements.md b/.ideas/future_improvements.md
new file mode 100644
index 0000000..391b41d
--- /dev/null
+++ b/.ideas/future_improvements.md
@@ -0,0 +1,7 @@
+# Future Improvements
+
+This file contains a list of ideas for future improvements to the Enchantrix library.
+
+-   **Fully implement the PGP module:** The PGP module is currently commented out due to dependency issues. This needs to be resolved so that the PGP functionality can be used.
+-   **Define the `.trix` file format:** The `.trix` file format needs to be defined and implemented. This will be the standard file format for encrypted data.
+-   **Build the rootFS passthrough storage:** The rootFS passthrough storage needs to be built. This will allow Web3 apps to use Enchantrix to give clients private keys securely.
diff --git a/chachapoly/chachapoly.go b/chachapoly/chachapoly.go
index 60f356a..2520c67 100644
--- a/chachapoly/chachapoly.go
+++ b/chachapoly/chachapoly.go
@@ -10,9 +10,6 @@ import (
 
 // Encrypt encrypts data using ChaCha20-Poly1305.
 func Encrypt(plaintext []byte, key []byte) ([]byte, error) {
-	if len(key) != chacha20poly1305.KeySize {
-		return nil, fmt.Errorf("invalid key size: got %d bytes, want %d bytes", len(key), chacha20poly1305.KeySize)
-	}
 	aead, err := chacha20poly1305.NewX(key)
 	if err != nil {
 		return nil, err
@@ -28,9 +25,6 @@ func Encrypt(plaintext []byte, key []byte) ([]byte, error) {
 
 // Decrypt decrypts data using ChaCha20-Poly1305.
 func Decrypt(ciphertext []byte, key []byte) ([]byte, error) {
-	if len(key) != chacha20poly1305.KeySize {
-		return nil, fmt.Errorf("invalid key size: got %d bytes, want %d bytes", len(key), chacha20poly1305.KeySize)
-	}
 	aead, err := chacha20poly1305.NewX(key)
 	if err != nil {
 		return nil, err
@@ -43,5 +37,14 @@ func Decrypt(ciphertext []byte, key []byte) ([]byte, error) {
 
 	nonce, ciphertext := ciphertext[:aead.NonceSize()], ciphertext[aead.NonceSize():]
 
-	return aead.Open(nil, nonce, ciphertext, nil)
+	decrypted, err := aead.Open(nil, nonce, ciphertext, nil)
+	if err != nil {
+		return nil, err
+	}
+
+	if len(decrypted) == 0 {
+		return []byte{}, nil
+	}
+
+	return decrypted, nil
 }
diff --git a/chachapoly/chachapoly_test.go b/chachapoly/chachapoly_test.go
index fb5ef73..539569d 100644
--- a/chachapoly/chachapoly_test.go
+++ b/chachapoly/chachapoly_test.go
@@ -21,3 +21,65 @@ func TestEncryptDecrypt(t *testing.T) {
 
 	assert.Equal(t, plaintext, decrypted)
 }
+
+func TestEncryptInvalidKeySize(t *testing.T) {
+	key := make([]byte, 16) // Wrong size
+	plaintext := []byte("test")
+	_, err := Encrypt(plaintext, key)
+	assert.Error(t, err)
+}
+
+func TestDecryptWithWrongKey(t *testing.T) {
+	key1 := make([]byte, 32)
+	key2 := make([]byte, 32)
+	key2[0] = 1 // Different key
+
+	plaintext := []byte("secret")
+	ciphertext, err := Encrypt(plaintext, key1)
+	assert.NoError(t, err)
+
+	_, err = Decrypt(ciphertext, key2)
+	assert.Error(t, err) // Should fail authentication
+}
+
+func TestDecryptTamperedCiphertext(t *testing.T) {
+	key := make([]byte, 32)
+	plaintext := []byte("secret")
+	ciphertext, err := Encrypt(plaintext, key)
+	assert.NoError(t, err)
+
+	// Tamper with the ciphertext
+	ciphertext[0] ^= 0xff
+
+	_, err = Decrypt(ciphertext, key)
+	assert.Error(t, err)
+}
+
+func TestEncryptEmptyPlaintext(t *testing.T) {
+	key := make([]byte, 32)
+	plaintext := []byte("")
+	ciphertext, err := Encrypt(plaintext, key)
+	assert.NoError(t, err)
+
+	decrypted, err := Decrypt(ciphertext, key)
+	assert.NoError(t, err)
+
+	assert.Equal(t, plaintext, decrypted)
+}
+
+func TestDecryptShortCiphertext(t *testing.T) {
+	key := make([]byte, 32)
+	shortCiphertext := []byte("short")
+
+	_, err := Decrypt(shortCiphertext, key)
+	assert.Error(t, err)
+	assert.Contains(t, err.Error(), "too short")
+}
+
+func TestCiphertextDiffersFromPlaintext(t *testing.T) {
+	key := make([]byte, 32)
+	plaintext := []byte("Hello, world!")
+	ciphertext, err := Encrypt(plaintext, key)
+	assert.NoError(t, err)
+	assert.NotEqual(t, plaintext, ciphertext)
+}