diff --git a/y/encrypt_test.go b/y/encrypt_test.go
new file mode 100644
index 000000000..91d50acb1
--- /dev/null
+++ b/y/encrypt_test.go
@@ -0,0 +1,64 @@
+/*
+ * Copyright 2020 Dgraph Labs, Inc. and Contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package y
+
+import (
+	"crypto/aes"
+	"crypto/rand"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestXORBlock(t *testing.T) {
+	key := make([]byte, 32)
+	rand.Read(key)
+
+	var iv []byte
+	{
+		b, err := aes.NewCipher(key)
+		require.NoError(t, err)
+		iv = make([]byte, b.BlockSize())
+		rand.Read(iv)
+		t.Logf("Using %d size IV\n", len(iv))
+	}
+
+	src := make([]byte, 1024)
+	rand.Read(src)
+
+	dst := make([]byte, 1024)
+	err := XORBlock(dst, src, key, iv)
+	require.NoError(t, err)
+
+	act := make([]byte, 1024)
+	err = XORBlock(act, dst, key, iv)
+	require.NoError(t, err)
+	require.Equal(t, src, act)
+
+	// Now check if we can use the same byte slice as src and dst. While this is useful to know that
+	// we can use src and dst as the same slice, this isn't applicable to Badger because we're
+	// reading data right off mmap. We should not modify that data, so we have to use a different
+	// slice for dst anyway.
+	cp := append([]byte{}, src...)
+	err = XORBlock(cp, cp, key, iv)
+	require.NoError(t, err)
+	require.Equal(t, dst, cp)
+
+	err = XORBlock(cp, cp, key, iv)
+	require.NoError(t, err)
+	require.Equal(t, src, cp)
+}