feat: still working

README.md

@@ -7,7 +7,7 @@ In stage 1 we only encrypt file content, the file name is not encrypted.
 In the future we are going to encrypt the file name also.
 
 
-<br>
+## AES-CTR Introduction
 
 AES-CTR algorithm is show as: https://git.hatter.ink/hatter/simple-rust-tests/src/branch/master/__crypto/aes_ctr_test/src/main.rs
 
@@ -31,7 +31,20 @@ for counter in 0..plaintext_block_count {
 }
 ```
 
-<br>
+## EncFile Spec
+
+File ext `*.__encfile`:
+
+```json
+{
+    "iv": "<16 bytes IV in base64>"
+}
+```
+
+> if `*.__encfile` not found, then file is unencrypted.
+
+
+## Reference
 
 Related projects:
 * https://github.com/spf13/afero