diff --git a/Cargo.toml b/Cargo.toml
index bc3b9ac..1abc68f 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,9 +1,9 @@
 [package]
 name = "sm9"
-version = "0.2.4"
+version = "0.2.5"
 edition = "2021"
 authors = ["John Yu <cb8866@sina.com>"]
-description = "SM9, identity-based cryptography"
+description = "SM9 (OSCCA GM/T 0044-2016), identity-based cryptography"
 keywords = ["SM9", "pairing", "crypto", "cryptography", "shangmi"]
 license = "MIT OR Apache-2.0"
 documentation = "https://docs.rs/sm9/"
@@ -18,7 +18,7 @@ sec1 = { version = "0.7.3", features = ["alloc", "pem", "std"] }
 sm3 = "0.4.2"
 hmac = "0.12.1"
 signature = "2.2.0"
-sm9_core = "0.3.4"
+sm9_core = "0.3.6"
 hex-literal = "0.4"
 kem = "0.2.0"
 
diff --git a/README.md b/README.md
index 25d0317..bc83eb1 100644
--- a/README.md
+++ b/README.md
@@ -8,7 +8,7 @@ Add the `sm9` crate to your dependencies in `Cargo.toml`
 
 ```toml
 [dependencies]
-sm9 = "0.2.3"
+sm9 = "0.2.5"
 ```
 
 ### Examples
@@ -27,6 +27,20 @@ sm9 = "0.2.3"
     println!("{:02X?}", msg);
     assert_eq!(msg.len(), txt.len());
     assert_eq!(txt, msg.as_slice());
+
+    use std::fs;    
+    let master_public_key =
+        fs::read_to_string("master_public_key.pem").expect("read master_public_key.pem error");
+    let m = Sm9::encrypt2(&master_public_key, usr_id, txt);
+    println!("{:02X?}", m);
+
+    let bob_private_key =
+        fs::read_to_string("bob_private_key.pem").expect("read bob_private_key.pem error");
+    let msg = Sm9::decrypt2(&bob_private_key, usr_id, m).expect("decrypt error");
+    println!("{:02X?}", msg);
+    assert_eq!(msg.len(), txt.len());
+    assert_eq!(txt, msg.as_slice());
+
 ```
 
 (See `signature.rs` for the full example.)
@@ -50,6 +64,19 @@ sm9 = "0.2.3"
         m,
         &sig
     ));
+    use std::fs;
+    let master_signature_public_key = fs::read_to_string("master_signature_public_key.pem")
+        .expect("read master_signature_public_key.pem error");
+    let alice_signature_private_key = fs::read_to_string("alice_signature_private_key.pem")
+        .expect("read alice_signature_private_key.pem error");
+    let sig = Sm9::sign2(
+        &master_signature_public_key,
+        &alice_signature_private_key,
+        m,
+    );
+
+    assert!(Sm9::verify2(&master_signature_public_key, user_id, m, &sig));
+
 ```
 
 ## License
@@ -61,7 +88,7 @@ Licensed under either of
 
 at your option.
 
-Copyright 2023 [John-Yu](https://github.com/John-Yu).
+Copyright 2024 [John-Yu](https://github.com/John-Yu).
 
 ### Authors
 
diff --git a/src/lib.rs b/src/lib.rs
index a62350e..6f1a0fe 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -193,6 +193,13 @@ impl Sm9 {
         assert!(mpk.is_ok());
         mpk.encrypt(usr_id, txt)
     }
+    // issues#1, use the content of a pem file as  parameter
+    pub fn encrypt2(master_public_key_pem: &str, usr_id: &[u8], txt: &[u8]) -> Vec<u8> {
+        let mpk = MasterPublicKey::from_pem(master_public_key_pem)
+            .expect("from_pem master_public_key_pem error");
+        assert!(mpk.is_ok());
+        mpk.encrypt(usr_id, txt)
+    }
     /// decrypt, difined in "SM9 identity-based cryptographic algorithms"
     /// Part 4: Key encapsulation mechanism and public key encryption algorithm
     /// 7.2.1 Decryption algorithm
@@ -206,6 +213,13 @@ impl Sm9 {
         assert!(upk.is_ok());
         upk.decrypt(usr_id, m)
     }
+    // issues#1, use the content of a pem file as  parameter
+    pub fn decrypt2(user_privte_key_pem: &str, usr_id: &[u8], m: Vec<u8>) -> Option<Vec<u8>> {
+        let upk = UserPrivateKey::from_pem(user_privte_key_pem)
+            .expect("from_pem user_privte_key_pem error");
+        assert!(upk.is_ok());
+        upk.decrypt(usr_id, m)
+    }
     /// sign, difined in "SM9 identity-based cryptographic algorithms"
     /// Part 2: Digital signature algorithm
     /// 6.1 Digital signature generation algorithm
@@ -230,7 +244,7 @@ impl Sm9 {
         m: &[u8],
     ) -> Signature {
         let uspk = UserSignaturePrivateKey::from_pem(user_signature_privte_key_pem)
-            .expect("read UserSignaturePrivateKey error");
+            .expect("from_pem UserSignaturePrivateKey error");
         assert!(uspk.is_ok());
         let mspk = MasterSignaturePublicKey::from_pem(master_signature_public_key_pem)
             .expect("MasterSignaturePublicKey from_pem error!");
diff --git a/tests/encryption.rs b/tests/encryption.rs
index 4599d45..6e89c9f 100644
--- a/tests/encryption.rs
+++ b/tests/encryption.rs
@@ -1,4 +1,5 @@
 use sm9::*;
+use std::fs;
 
 #[test]
 fn test_encrypt_decrypt() {
@@ -15,3 +16,22 @@ fn test_encrypt_decrypt() {
     assert_eq!(msg.len(), txt.len());
     assert_eq!(txt, msg.as_slice());
 }
+#[test]
+fn test_encrypt_decrypt2() {
+    // SM9 identity-based cryptographic algorithms
+    // Part 5: Parameter definition
+    // Annex D: Example of public key encryption
+    let usr_id = b"Bob";
+    let txt = b"Chinese IBE standard";
+    let master_public_key =
+        fs::read_to_string("master_public_key.pem").expect("read master_public_key.pem error");
+    let m = Sm9::encrypt2(&master_public_key, usr_id, txt);
+    println!("{:02X?}", m);
+
+    let bob_private_key =
+        fs::read_to_string("bob_private_key.pem").expect("read bob_private_key.pem error");
+    let msg = Sm9::decrypt2(&bob_private_key, usr_id, m).expect("decrypt error");
+    println!("{:02X?}", msg);
+    assert_eq!(msg.len(), txt.len());
+    assert_eq!(txt, msg.as_slice());
+}