diff --git a/README.md b/README.md
index 6bec6ab..fd7852b 100644
--- a/README.md
+++ b/README.md
@@ -25,6 +25,7 @@ other languages.
 - Diamond (https://www.codewars.com/kata/5503013e34137eeeaa001648)
 - Fibonacci Product (https://www.codewars.com/kata/5541f58a944b85ce6d00006a)
 - Valid Parentheses (https://www.codewars.com/kata/52774a314c2333f0a7000688)
+- Alphanumeric (https://www.codewars.com/kata/526dbd6c8c0eb53254000110)
 
 #### Kata 6
 
diff --git a/src/codewars/mod.rs b/src/codewars/mod.rs
index 6cb13b8..14c42da 100644
--- a/src/codewars/mod.rs
+++ b/src/codewars/mod.rs
@@ -43,3 +43,4 @@ mod camel_case;
 mod cats_and_shelves;
 mod people_on_the_bus;
 mod summation;
+mod not_secure;
diff --git a/src/codewars/not_secure.rs b/src/codewars/not_secure.rs
new file mode 100644
index 0000000..d82cace
--- /dev/null
+++ b/src/codewars/not_secure.rs
@@ -0,0 +1,38 @@
+// Regex solution
+// use regex::Regex;
+//
+// fn alphanumeric(password: &str) -> bool {
+//     let regex = Regex::new("^[a-zA-Z0-9]+$").unwrap();
+//     regex.is_match(password)
+// }
+
+fn alphanumeric(password: &str) -> bool {
+    !password.is_empty() && password.chars().all(char::is_alphanumeric)
+}
+
+#[cfg(test)]
+mod tests {
+    use test_case::test_case;
+
+    use crate::codewars::not_secure::alphanumeric;
+
+    #[test]
+    fn should_return_false_when_value_is_empty() {
+        let actual = alphanumeric("");
+        assert_eq!(actual, false);
+    }
+
+    #[test_case("hello", true)]
+    #[test_case("PassW0rd", true)]
+    fn should_return_true_when_value_is_alphanumeric(value: &str, expected: bool) {
+        let actual = alphanumeric(value);
+        assert_eq!(actual, expected);
+    }
+
+    #[test_case("hello world_", false)]
+    #[test_case("   ", false)]
+    fn should_return_false_when_value_is_not_alphanumeric(value: &str, expected: bool) {
+        let actual = alphanumeric(value);
+        assert_eq!(actual, expected);
+    }
+}