diff --git a/__enclave/virt_enclave/examples/verify_file.rs b/__enclave/virt_enclave/examples/verify_file.rs
new file mode 100644
index 0000000..be60539
--- /dev/null
+++ b/__enclave/virt_enclave/examples/verify_file.rs
@@ -0,0 +1,53 @@
+use std::io::Read;
+use std::fs::File;
+use ring::digest;
+use virt_enclave::sig::*;
+
+fn main() {
+    let mut args = std::env::args();
+    args.next();
+    let signing_key_pair = match SigningKeyPair::read_from_file("platform_signing_key.json") {
+        Err(_) => { println!("Read file failed!"); return; },
+        Ok(k) => k,
+    };
+    let f = match args.next() {
+        None => { println!("File not assigned!"); return; },
+        Some(f) => f,
+    };
+    let sf = match args.next() {
+        None => { println!("Sign file not assigned!"); return; },
+        Some(f) => f,
+    };
+    let mut file = match File::open(&f) {
+        Err(_) => { println!("Open file failed: {}", f); return; }
+        Ok(f) => f,
+    };
+    let mut sign_file = match File::open(&sf) {
+        Err(_) => { println!("Open sign file failed: {}", sf); return; }
+        Ok(f) => f,
+    };
+    let mut buf = vec![];
+    let _len = match file.read_to_end(&mut buf) {
+        Err(_) => { println!("Read file failed: {}", f); return; }
+        Ok(c) => c,
+    };
+    let mut sign_buf = vec![];
+    let _sig_len = match sign_file.read_to_end(&mut sign_buf) {
+        Err(_) => { println!("Read file failed: {}", sf); return; }
+        Ok(c) => c,
+    };
+    let signed_message = match serde_json::from_str::<SignedMessage>(&String::from_utf8(sign_buf).unwrap()) {
+        Err(_) => { println!("Parse sign file failed: {}", sf); return; }
+        Ok(m) => m,
+    };
+    let d = digest::digest(&digest::SHA256, &buf);
+    let matches  = d.as_ref().to_vec() == signed_message.msg.clone();
+
+    let digest_hex = hex::encode(&d);
+    let msg = &signed_message.msg;
+
+    println!("File  : {}", f);
+    println!("Hex   : {}", digest_hex);
+    println!("SHex  : {}  - {}", hex::encode(msg), if matches { "matches"} else { "NOT matched" });
+    println!("Signed: {}", signed_message.verify(&signing_key_pair.public_key()));
+}
\ No newline at end of file
diff --git a/__enclave/virt_enclave/src/sig.rs b/__enclave/virt_enclave/src/sig.rs
index 1301c1d..8374a96 100644
--- a/__enclave/virt_enclave/src/sig.rs
+++ b/__enclave/virt_enclave/src/sig.rs
@@ -75,9 +75,9 @@ impl SigningKeyPair {
 
 #[derive(Serialize, Deserialize)]
 pub struct SignedMessage {
-    msg: Vec<u8>,
-    sig: Option<Vec<u8>>,
-    desc: Option<String>,
+    pub msg: Vec<u8>,
+    pub sig: Option<Vec<u8>>,
+    pub desc: Option<String>,
 }
 
 impl SignedMessage {