diff --git a/examples/test.rs b/examples/test.rs
index 5f90f01..f58b5ee 100644
--- a/examples/test.rs
+++ b/examples/test.rs
@@ -6,9 +6,7 @@
 
 use std::ffi::CStr;
 //use rustylib::gen::{CWallet};
-use rustwallet::{
-    fetch_cwallet, free_cwallet, generate_cwallet, save_wallet, sign, sss_sign, CWallet,
-};
+use rustwallet::{fetch_cwallet, free_cwallet, sign, sss_sign, CWallet};
 
 fn main() {
     unsafe {
@@ -24,7 +22,9 @@ fn main() {
         let fetched = fetch_cwallet();
         print_wallet(&fetched);
         sign();
-        sss_sign();
+        let sign_str = "111";
+        let cstr = std::ffi::CString::new(sign_str).unwrap();
+        sss_sign(cstr.into_raw());
 
         // free_cwallet(wallet); // 对应 generate_cwallet()
         free_cwallet(fetched); // 对应 fetch_wallet()
diff --git a/src/lib.rs b/src/lib.rs
index fa16efb..d6ecd46 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -73,29 +73,28 @@ pub unsafe extern "C" fn sign() {
         Err(_) => {
             println!("error sign");
         }
-        Ok(w) => {
-            match w.sign("111") {
-                Err(err) => {
-                    println!("error sign: {:?}", err);
-                }
-                Ok(sig) => {
-                    println!("sig result: {:?}", sig);
-                }
+        Ok(w) => match w.sign("111") {
+            Err(err) => {
+                println!("error sign: {:?}", err);
             }
-
-        } 
+            Ok(sig) => {
+                println!("sig result: {:?}", sig);
+            }
+        },
     };
 }
 
 #[no_mangle]
-pub unsafe extern "C" fn sss_sign() {
+pub unsafe extern "C" fn sss_sign(msg: *const std::os::raw::c_char) {
+    let c_str = CStr::from_ptr(msg);
+    let str = c_str.to_str().unwrap();
     match wallet_impl::Wallet::retrieve_keys("wallet.json") {
         Err(_) => {
             println!("error sign");
         }
         Ok(w) => {
-            w.sss_sign();
-        } 
+            w.sss_sign(&str);
+        }
     };
 }
 
diff --git a/src/wallet/wallet_impl.rs b/src/wallet/wallet_impl.rs
index 0426ed3..5aee84b 100644
--- a/src/wallet/wallet_impl.rs
+++ b/src/wallet/wallet_impl.rs
@@ -1,19 +1,19 @@
 extern crate hex;
 
 use anyhow::Result;
-use secp256k1::{PublicKey, SecretKey, Message, Secp256k1};
+use core::fmt::Write;
 use secp256k1::rand::rngs::OsRng;
+use secp256k1::{Message, PublicKey, Secp256k1, SecretKey};
 use serde::{Deserialize, Serialize};
+use shamir_secret_sharing::num_bigint::BigInt;
+use shamir_secret_sharing::ShamirSecretSharing as SSS;
 use std::io::BufWriter;
+use std::str;
 use std::str::FromStr;
 use std::{fs::OpenOptions, io::BufReader};
 use tiny_keccak::keccak256;
+use web3::signing::{hash_message, Key, SecretKeyRef};
 use web3::types::Address;
-use web3::signing::{ hash_message, SecretKeyRef, Key };
-use std::str;
-use core::fmt::Write;
-use shamir_secret_sharing::num_bigint::BigInt;
-use shamir_secret_sharing::ShamirSecretSharing as SSS;
 
 pub fn generate_keypair() -> (SecretKey, PublicKey) {
     let secp = Secp256k1::new();
@@ -29,7 +29,6 @@ pub fn public_key_address(public_key: &PublicKey) -> Address {
     Address::from_slice(&hash[12..])
 }
 
-
 #[derive(Serialize, Deserialize, Debug)]
 pub struct Wallet {
     pub secret_key: String,
@@ -41,13 +40,9 @@ impl Wallet {
     pub fn new(secret_key: &SecretKey, public_key: &PublicKey) -> Self {
         let addr: Address = public_key_address(&public_key);
         println!("secret key: {:?}", secret_key);
-        let mut s = String::with_capacity(2 * 32);
-        for i in &secret_key.serialize_secret() {
-            write!(s, "{:02x}", *i).unwrap();
-        }
+        let s = hex::encode(&secret_key.serialize_secret());
         println!("{:?}", s);
 
-        
         Wallet {
             secret_key: s,
             public_key: public_key.to_string(),
@@ -61,7 +56,6 @@ impl Wallet {
             .create(true)
             .open(file_path)?;
         let buf_writer = BufWriter::new(file);
-
         serde_json::to_writer_pretty(buf_writer, self)?;
 
         Ok(())
@@ -70,28 +64,30 @@ impl Wallet {
     pub fn retrieve_keys(file_path: &str) -> Result<Wallet> {
         let file = OpenOptions::new().read(true).open(file_path)?;
         let buf_reader = BufReader::new(file);
-
         let wallet: Wallet = serde_json::from_reader(buf_reader)?;
+
         Ok(wallet)
     }
 
-    pub fn sss_sign(&self) {
+    pub fn sss_sign(&self, msg: &str) {
+        let k_hash = keccak256(msg.as_bytes());
+        println!("k_hash: {:?}", &k_hash);
+        let s = hex::encode(&k_hash);
+        println!("k_hash str: {:?}", &s);
+        println!("k_hash byte: {:?}", &s.as_bytes());
+        let pb = BigInt::parse_bytes(&s.as_bytes(), 16).unwrap();
         let sss = SSS {
             threshold: 2,
             share_amount: 3,
-            prime: BigInt::parse_bytes(
-                b"fffffffffffffffffffffffffffffffffffffffffffffffffffffffefffffc2f",
-                16,
-            )
-            .unwrap(),
+            prime: pb,
         };
-    
+
         let secret = BigInt::parse_bytes(
             b"64a6f7baa58d7381f4068fc729568009ef8f36e9c7d9c33d2cf06afc25c01e87",
             16,
         )
         .unwrap();
-    
+
         let shares = sss.split(secret.clone());
         let key0 = shares[1].clone().1;
         let key1 = shares[2].clone().1;
@@ -107,18 +103,21 @@ impl Wallet {
         println!("recover: {:?}", secret_b.to_str_radix(16));
     }
 
-    pub fn sign<S>(&self, msg: S) -> Result<()> 
-        where
-            S: AsRef<[u8]>,{
+    pub fn sign<S>(&self, msg: S) -> Result<()>
+    where
+        S: AsRef<[u8]>,
+    {
         let secp = Secp256k1::new();
         println!("secret key str: {:?}", self.secret_key);
         let message = msg.as_ref();
         let message_hash = hash_message(message.as_ref());
         let pk = SecretKey::from_str(&self.secret_key).expect("32 bytes, within curve order");
         println!("secret key: {:?}", pk);
-        
+
         let key = SecretKeyRef::new(&pk);
-        let signature = key.sign(message_hash.as_bytes(), None).expect("hash is non-zero 32-bytes; qed");
+        let signature = key
+            .sign(message_hash.as_bytes(), None)
+            .expect("hash is non-zero 32-bytes; qed");
         let v = signature
             .v
             .try_into()
@@ -137,20 +136,22 @@ impl Wallet {
         bytes.extend_from_slice(signature.s.as_bytes());
         bytes.push(v);
 
-        let mut str_sign = String::with_capacity(2 * 65);
-        for i in bytes.iter() {
-            write!(str_sign, "{:02x}", i).unwrap();
-        }
+        let str_sign = hex::encode(bytes);
         println!("web3 sign: {:?}", str_sign);
-        
+
         let message_to_hash = Message::from_slice(message_hash.as_ref()).unwrap();
-        let (recovery_id, signature) = secp.sign_ecdsa_recoverable(&message_to_hash, &pk).serialize_compact();
-        let mut s = String::with_capacity(2 * 65);
-        for i in signature {
-            write!(s, "{:02x}", i).unwrap();
-        }
+        let (recovery_id, signature) = secp
+            .sign_ecdsa_recoverable(&message_to_hash, &pk)
+            .serialize_compact();
+        // let mut s = String::with_capacity(2 * 65);
+        // for i in signature {
+        //     write!(s, "{:02x}", i).unwrap();
+        // }
+        let mut s = hex::encode(signature);
         let standard_v = recovery_id.to_i32() as u64 + 27;
-        let rv:u8 = standard_v.try_into().expect("signature recovery in electrum notation always fits in a u8");
+        let rv: u8 = standard_v
+            .try_into()
+            .expect("signature recovery in electrum notation always fits in a u8");
         write!(s, "{:02x}", rv).unwrap();
         println!("normal sigx: {:?}", s);