diff --git a/db/db-core/Cargo.toml b/db/db-core/Cargo.toml
index 3a7c6ee0..d0d3350f 100644
--- a/db/db-core/Cargo.toml
+++ b/db/db-core/Cargo.toml
@@ -13,6 +13,7 @@ async-trait = "0.1.51"
 thiserror = "1.0.30"
 serde = { version = "1", features = ["derive"]}
 url = { version  = "2.2.2", features = ["serde"] }
+libmcaptcha = { branch = "master", git = "https://github.com/mCaptcha/libmcaptcha", features = ["minimal"], default-features = false }
 
 [features]
 default = []
diff --git a/db/db-core/src/errors.rs b/db/db-core/src/errors.rs
index 3ecb09c3..07e3b0f6 100644
--- a/db/db-core/src/errors.rs
+++ b/db/db-core/src/errors.rs
@@ -35,6 +35,9 @@ pub enum DBError {
     /// Secret is taken
     #[error("Secret is taken")]
     SecretTaken,
+    /// Captcha key is taken
+    #[error("Captcha key is taken")]
+    CaptchaKeyTaken,
 }
 
 /// Convenience type alias for grouping driver-specific errors
diff --git a/db/db-core/src/lib.rs b/db/db-core/src/lib.rs
index 0ec37061..75770cf8 100644
--- a/db/db-core/src/lib.rs
+++ b/db/db-core/src/lib.rs
@@ -33,6 +33,8 @@
 //! connection from pool
 use serde::{Deserialize, Serialize};
 
+use libmcaptcha::defense::Level;
+
 pub mod errors;
 pub mod ops;
 #[cfg(feature = "test")]
@@ -131,6 +133,20 @@ pub trait MCDatabase: std::marker::Send + std::marker::Sync + CloneSPDatabase {
 
     /// update a user's secret
     async fn update_secret(&self, username: &str, secret: &str) -> DBResult<()>;
+
+    /// create new captcha
+    async fn create_captcha(&self, username: &str, p: &CreateCaptcha) -> DBResult<()>;
+}
+
+#[derive(Clone, Debug, Default, Deserialize, Serialize)]
+/// data requried to create new captcha
+pub struct CreateCaptcha<'a> {
+    /// cool down duration
+    pub duration: i32,
+    /// description of the captcha
+    pub description: &'a str,
+    /// secret key of the captcha
+    pub key: &'a str,
 }
 
 #[derive(Clone, Debug, Deserialize, Serialize)]
diff --git a/db/db-core/src/tests.rs b/db/db-core/src/tests.rs
index 3ef9548d..58e92bc8 100644
--- a/db/db-core/src/tests.rs
+++ b/db/db-core/src/tests.rs
@@ -18,7 +18,11 @@
 use crate::prelude::*;
 
 /// test all database functions
-pub async fn database_works<'a, T: MCDatabase>(db: &T, p: &Register<'a>) {
+pub async fn database_works<'a, T: MCDatabase>(
+    db: &T,
+    p: &Register<'a>,
+    c: &CreateCaptcha<'a>,
+) {
     assert!(db.ping().await, "ping test");
     if db.username_exists(p.username).await.unwrap() {
         db.delete_user(p.username).await.unwrap();
@@ -125,4 +129,6 @@ pub async fn database_works<'a, T: MCDatabase>(db: &T, p: &Register<'a>) {
         db.email_exists(p.email.as_ref().unwrap()).await.unwrap(),
         "user was with empty email but email is set; so email should exsit"
     );
+
+    db.create_captcha(&p.username, c).await.unwrap();
 }