diff --git a/Cargo.lock b/Cargo.lock
index 5c5e5e9..4a36088 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -60,9 +60,9 @@ dependencies = [
 
 [[package]]
 name = "anstream"
-version = "0.6.18"
+version = "0.6.19"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8acc5369981196006228e28809f761875c0327210a891e941f4c683b3a99529b"
+checksum = "301af1932e46185686725e0fad2f8f2aa7da69dd70bf6ecc44d6b703844a3933"
 dependencies = [
  "anstyle",
  "anstyle-parse",
@@ -75,33 +75,33 @@ dependencies = [
 
 [[package]]
 name = "anstyle"
-version = "1.0.10"
+version = "1.0.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "55cc3b69f167a1ef2e161439aa98aed94e6028e5f9a59be9a6ffb47aef1651f9"
+checksum = "862ed96ca487e809f1c8e5a8447f6ee2cf102f846893800b20cebdf541fc6bbd"
 
 [[package]]
 name = "anstyle-parse"
-version = "0.2.6"
+version = "0.2.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3b2d16507662817a6a20a9ea92df6652ee4f94f914589377d69f3b21bc5798a9"
+checksum = "4e7644824f0aa2c7b9384579234ef10eb7efb6a0deb83f9630a49594dd9c15c2"
 dependencies = [
  "utf8parse",
 ]
 
 [[package]]
 name = "anstyle-query"
-version = "1.1.2"
+version = "1.1.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "79947af37f4177cfead1110013d678905c37501914fba0efea834c3fe9a8d60c"
+checksum = "6c8bdeb6047d8983be085bab0ba1472e6dc604e7041dbf6fcd5e71523014fae9"
 dependencies = [
  "windows-sys 0.59.0",
 ]
 
 [[package]]
 name = "anstyle-wincon"
-version = "3.0.8"
+version = "3.0.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6680de5231bd6ee4c6191b8a1325daa282b415391ec9d3a37bd34f2060dc73fa"
+checksum = "403f75924867bb1033c59fbf0797484329750cfbe3c4325cd33127941fabc882"
 dependencies = [
  "anstyle",
  "once_cell_polyfill",
@@ -267,9 +267,9 @@ dependencies = [
 
 [[package]]
 name = "axum-jwt-login"
-version = "0.1.1"
+version = "0.1.2"
 source = "sparse+https://crates.esteil.dedyn.io/api/v1/crates/"
-checksum = "b45378650bae1dfcc3ed411ffc7b2bfe5977f6c3de5f140993b1ee2979cccc4c"
+checksum = "7866571ffba399da64ce58fab21c6eb0ad76a312ec7d546d5dfada2435ab26ea"
 dependencies = [
  "axum",
  "chrono",
@@ -322,9 +322,9 @@ checksum = "72b3254f16251a8381aa12e40e3c4d2f0199f8c6508fbecb9d91f575e0fbb8c6"
 
 [[package]]
 name = "base64ct"
-version = "1.7.3"
+version = "1.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "89e25b6adfb930f02d1981565a6e5d9c547ac15a96606256d3b59040e5cd4ca3"
+checksum = "55248b47b0caf0546f7988906588779981c43bb1bc9d0c44087278f80cdb44ba"
 
 [[package]]
 name = "bitflags"
@@ -489,9 +489,9 @@ checksum = "f46ad14479a25103f283c0f10005961cf086d8dc42205bb44c46ac563475dca6"
 
 [[package]]
 name = "colorchoice"
-version = "1.0.3"
+version = "1.0.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5b63caa9aa9397e2d9480a9b13673856c78d8ac123288526c37d7839f2a86990"
+checksum = "b05b61dc5112cbb17e4b6cd61790d9845d13888356391624cbe7e41efeac1e75"
 
 [[package]]
 name = "colored"
@@ -1187,9 +1187,9 @@ dependencies = [
 
 [[package]]
 name = "hyper-util"
-version = "0.1.13"
+version = "0.1.14"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b1c293b6b3d21eca78250dc7dbebd6b9210ec5530e038cbfe0661b5c47ab06e8"
+checksum = "dc2fdfdbff08affe55bb779f33b053aa1fe5dd5b54c257343c17edfa55711bdb"
 dependencies = [
  "bytes",
  "futures-core",
diff --git a/Cargo.toml b/Cargo.toml
index bc3b1e0..a7ac8b7 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -27,7 +27,7 @@ colored = "3.0.0"
 uuid = { version = "1.17.0", features = ["v4"] }
 blake3 = "1.1.18"
 minisign = "0.7.9"
-axum-jwt-login = { version = "0.1.1", registry = "kellnr" }
+axum-jwt-login = { version = "0.1.2", registry = "kellnr" }
 rust-argon2 = "2.1.0"
 rand = "0.9.1"
 ldap3 = "0.11.5"
diff --git a/src/api/backend/integrity_verification.rs b/src/api/backend/integrity_verification.rs
index b372462..160c0ef 100644
--- a/src/api/backend/integrity_verification.rs
+++ b/src/api/backend/integrity_verification.rs
@@ -17,13 +17,13 @@ pub struct IntegrityVerifier {
 }
 
 impl IntegrityVerifier {
-    pub fn new() -> Result<Self, ApiError> {
-        Ok(Self {
+    pub fn new() -> Self {
+        Self {
             mac: Hasher::new_derive_key(include_str!("./verification_secret")),
-        })
+        }
     }
 
-    pub fn sign<T>(&self, data: &T) -> Result<Hash, ApiError>
+    pub fn sign<T>(&self, data: &T) -> Hash
     where
         T: CustomHash,
     {
@@ -33,7 +33,7 @@ impl IntegrityVerifier {
         let signature = mac.finalize();
         mac.reset();
 
-        Ok(signature)
+        signature
     }
 
     pub fn verify<T>(&self, data: &T, signature: Hash) -> Result<(), ApiError>
@@ -73,14 +73,14 @@ mod test {
             }
         }
 
-        let verifier = IntegrityVerifier::new().unwrap();
+        let verifier = IntegrityVerifier::new();
 
         let mut item = TestData {
             one: 24,
             two: "MyTesting".to_string(),
         };
 
-        let signature = verifier.sign(&item).unwrap();
+        let signature = verifier.sign(&item);
         assert!(verifier.verify(&item, signature).is_ok());
 
         item.two = "Wrong".to_string();
diff --git a/src/api/routes/api_keys/models.rs b/src/api/routes/api_keys/models.rs
index f1e8e04..4ef7556 100644
--- a/src/api/routes/api_keys/models.rs
+++ b/src/api/routes/api_keys/models.rs
@@ -1,4 +1,4 @@
-use std::collections::HashSet;
+use std::collections::BTreeSet;
 
 use axum_jwt_login::ApiKey as ApiKeyTrait;
 use blake3::{Hash, Hasher};
@@ -59,7 +59,7 @@ impl ApiKey {
     pub fn create(
         name: &str,
         requires_auth: bool,
-        permissions: HashSet<Permission>,
+        permissions: BTreeSet<Permission>,
         config: &Configuration,
     ) -> Result<(String, Self), ApiError> {
         // create uuid
@@ -128,14 +128,14 @@ impl ApiKeyTrait for ApiKey {
     fn requires_user_auth(&self) -> bool {
         self.auth_required
     }
-    fn get_permissions(&self) -> HashSet<Self::Permission> {
+    fn get_permissions(&self) -> BTreeSet<Self::Permission> {
         self.permissions.0.clone()
     }
 }
 
 #[cfg(test)]
 mod test {
-    use std::collections::HashSet;
+    use std::collections::BTreeSet;
 
     use crate::config::Configuration;
 
@@ -148,7 +148,7 @@ mod test {
             ..Default::default()
         };
         let (key, api_key) =
-            ApiKey::create("name", true, HashSet::new(), &config).expect("Error creating API Key");
+            ApiKey::create("name", true, BTreeSet::new(), &config).expect("Error creating API Key");
         println!("{key}, {api_key:?}");
         assert_eq!(Ok(()), api_key.validate(&key));
         assert_ne!(Ok(()), api_key.validate("124"));
diff --git a/src/api/routes/users/models.rs b/src/api/routes/users/models.rs
index fdb5320..9a09caf 100644
--- a/src/api/routes/users/models.rs
+++ b/src/api/routes/users/models.rs
@@ -1,5 +1,5 @@
 use std::{
-    collections::{HashMap, HashSet},
+    collections::{BTreeSet, HashMap, HashSet},
     fmt,
 };
 
@@ -12,7 +12,10 @@ use ts_rs::TS;
 use utoipa::ToSchema;
 
 use crate::{
-    api::routes::{departments::models::ShortDepartment, models::Status},
+    api::{
+        backend::integrity_verification::CustomHash,
+        routes::{departments::models::ShortDepartment, models::Status},
+    },
     errors::ApiError,
 };
 
@@ -104,6 +107,17 @@ impl fmt::Debug for User {
     }
 }
 
+impl CustomHash for User {
+    fn updater(&self, hasher: &mut blake3::Hasher) {
+        hasher.update(self.user_id.as_bytes());
+        hasher.update(self.name.as_bytes());
+        hasher.update(self.surname.as_bytes());
+        for permission in &self.permissions.0 {
+            hasher.update(permission.to_string().as_bytes());
+        }
+    }
+}
+
 impl UserPermissions for User {
     type Error = ApiError;
     type Permission = Permission;
@@ -113,10 +127,10 @@ impl UserPermissions for User {
         self.user_id.clone()
     }
 
-    fn get_user_permissions(&self) -> Result<HashSet<Self::Permission>, Self::Error> {
+    fn get_user_permissions(&self) -> Result<BTreeSet<Self::Permission>, Self::Error> {
         Ok(self.permissions.0.iter().cloned().collect())
     }
-    fn get_group_permissions(&self) -> Result<HashSet<Self::Permission>, Self::Error> {
+    fn get_group_permissions(&self) -> Result<BTreeSet<Self::Permission>, Self::Error> {
         Ok(self.group_permissions.0.iter().cloned().collect())
     }
 }
diff --git a/src/api/routes/users/permissions.rs b/src/api/routes/users/permissions.rs
index 6ea70eb..5a8f73e 100644
--- a/src/api/routes/users/permissions.rs
+++ b/src/api/routes/users/permissions.rs
@@ -1,11 +1,13 @@
-use std::{collections::HashSet, convert::Infallible, fmt::Display, str::FromStr};
+use std::{collections::BTreeSet, convert::Infallible, fmt::Display, str::FromStr};
 
 use serde::{Deserialize, Serialize};
 use strum::EnumString;
 use ts_rs::TS;
 use utoipa::ToSchema;
 
-#[derive(Debug, Clone, Copy, Serialize, Deserialize, PartialEq, Eq, Hash, TS, ToSchema)]
+#[derive(
+    Debug, Clone, Copy, Serialize, Deserialize, PartialEq, Eq, Hash, PartialOrd, Ord, TS, ToSchema,
+)]
 pub enum Permission {
     Read(PermissionDetail),
     Write(PermissionDetail),
@@ -52,6 +54,8 @@ impl Display for Permission {
     Deserialize,
     PartialEq,
     Eq,
+    PartialOrd,
+    Ord,
     Hash,
     EnumString,
     strum::Display,
@@ -70,17 +74,17 @@ pub enum PermissionDetail {
 }
 
 #[derive(Debug, Clone, Serialize, Deserialize, TS, ToSchema)]
-pub struct PermissionContainer(pub HashSet<Permission>);
+pub struct PermissionContainer(pub BTreeSet<Permission>);
 
 impl From<Option<Vec<String>>> for PermissionContainer {
     fn from(value: Option<Vec<String>>) -> Self {
         let set = match value {
-            Some(values) => HashSet::from_iter(
+            Some(values) => BTreeSet::from_iter(
                 values
                     .iter()
                     .map(|s| Permission::from_str(s).unwrap_or(Permission::None)),
             ),
-            None => HashSet::new(),
+            None => BTreeSet::new(),
         };
 
         Self(set)
@@ -89,9 +93,24 @@ impl From<Option<Vec<String>>> for PermissionContainer {
 
 #[cfg(test)]
 mod test {
-    use std::str::FromStr;
+    use std::{
+        collections::{BTreeSet, HashSet},
+        str::FromStr,
+    };
 
-    use crate::api::routes::users::permissions::PermissionDetail;
+    use chrono::Local;
+
+    use crate::api::{
+        backend::integrity_verification::IntegrityVerifier,
+        routes::{
+            departments::models::ShortDepartment,
+            models::Status,
+            users::{
+                models::{DepartmentContainer, GroupContainer, User},
+                permissions::{PermissionContainer, PermissionDetail},
+            },
+        },
+    };
 
     use super::Permission;
 
@@ -103,4 +122,41 @@ mod test {
         let parsed = Permission::from_str("Write:Users").unwrap();
         assert_eq!(parsed, Permission::Write(PermissionDetail::Users));
     }
+
+    #[tokio::test]
+    async fn test_integrity_validation() {
+        let mut user = User {
+            user_id: "id".to_string(),
+            active_directory_auth: false,
+            password: "Some PW".to_string(),
+            name: "Clark".to_string(),
+            surname: "Kent".to_string(),
+            email: "Superman@heros.com".to_string(),
+            department: DepartmentContainer(Some(ShortDepartment {
+                id: 1,
+                name: "Some name".to_string(),
+                description: None,
+            })),
+            groups: GroupContainer(HashSet::new()),
+            group_permissions: PermissionContainer(BTreeSet::new()),
+            permissions: PermissionContainer(BTreeSet::from_iter([Permission::Read(
+                PermissionDetail::Departments,
+            )])),
+            status_flag: Status::Active,
+            creation_date: Local::now().naive_local(),
+            last_change: Local::now().naive_local(),
+        };
+
+        let verifier = IntegrityVerifier::new();
+
+        let hash = verifier.sign(&user);
+
+        assert!(verifier.verify(&user, hash).is_ok());
+
+        user.permissions
+            .0
+            .insert(Permission::Write(PermissionDetail::Units));
+
+        assert!(verifier.verify(&user, hash).is_err());
+    }
 }
diff --git a/src/cli.rs b/src/cli.rs
index 9d62a2f..eb194a1 100644
--- a/src/cli.rs
+++ b/src/cli.rs
@@ -1,4 +1,4 @@
-use std::{collections::HashSet, path::PathBuf};
+use std::{collections::BTreeSet, path::PathBuf};
 
 use clap::{command, Parser, Subcommand};
 use colored::Colorize;
@@ -134,7 +134,7 @@ impl Cli {
                     } => {
                         // create API Key
                         let (key_secret, key) =
-                            ApiKey::create(name, *requires_auth, HashSet::new(), config)
+                            ApiKey::create(name, *requires_auth, BTreeSet::new(), config)
                                 .change_context(AppError)?;
 
                         // Add API Key to Database