diff --git a/virtweb_backend/src/utils/jwt_utils.rs b/virtweb_backend/src/utils/jwt_utils.rs
index 813f81c..aa379bc 100644
--- a/virtweb_backend/src/utils/jwt_utils.rs
+++ b/virtweb_backend/src/utils/jwt_utils.rs
@@ -83,18 +83,58 @@ mod test {
         exp: u64,
     }
 
+    impl Default for Claims {
+        fn default() -> Self {
+            Self {
+                sub: "my-sub".to_string(),
+                exp: time() + 100,
+            }
+        }
+    }
+
     #[test]
     fn jwt_encode_sign_verify_valid() {
         let (pub_key, priv_key) = generate_key_pair().unwrap();
-        let claims = Claims {
-            sub: "my-sub".to_string(),
-            exp: time() + 100,
-        };
+        let claims = Claims::default();
         let jwt = sign_jwt(&priv_key, &claims).expect("Failed to sign JWT!");
         let claims_out = validate_jwt(&pub_key, &jwt).expect("Failed to validate JWT!");
 
         assert_eq!(claims, claims_out)
     }
 
-    // TODO : complete tests
+    #[test]
+    fn jwt_encode_sign_verify_invalid_key() {
+        let (_pub_key, priv_key) = generate_key_pair().unwrap();
+        let (pub_key_2, _priv_key_2) = generate_key_pair().unwrap();
+        let claims = Claims::default();
+        let jwt = sign_jwt(&priv_key, &claims).expect("Failed to sign JWT!");
+        validate_jwt::<Claims>(&pub_key_2, &jwt).expect_err("JWT should not have validated!");
+    }
+
+    #[test]
+    fn jwt_verify_random_string() {
+        let (pub_key, _priv_key) = generate_key_pair().unwrap();
+        validate_jwt::<Claims>(&pub_key, "random_string")
+            .expect_err("JWT should not have validated!");
+    }
+
+    #[test]
+    fn jwt_expired() {
+        let (pub_key, priv_key) = generate_key_pair().unwrap();
+        let claims = Claims {
+            exp: time() - 100,
+            ..Default::default()
+        };
+        let jwt = sign_jwt(&priv_key, &claims).expect("Failed to sign JWT!");
+        validate_jwt::<Claims>(&pub_key, &jwt).expect_err("JWT should not have validated!");
+    }
+
+    #[test]
+    fn jwt_invalid_signature() {
+        let (pub_key, priv_key) = generate_key_pair().unwrap();
+        let claims = Claims::default();
+        let jwt = sign_jwt(&priv_key, &claims).expect("Failed to sign JWT!");
+        validate_jwt::<Claims>(&pub_key, &format!("{jwt}bad"))
+            .expect_err("JWT should not have validated!");
+    }
 }