diff --git a/services/commtest/src/identity/device.rs b/services/commtest/src/identity/device.rs
--- a/services/commtest/src/identity/device.rs
+++ b/services/commtest/src/identity/device.rs
@@ -2,6 +2,7 @@
 use grpc_clients::identity::{get_auth_client, get_unauthenticated_client};
 use rand::{distributions::Alphanumeric, Rng};
 
+use crate::identity::olm_account_infos::generate_random_olm_key;
 use crate::identity::olm_account_infos::{
   ClientPublicKeys, DEFAULT_CLIENT_KEYS,
 };
@@ -69,11 +70,11 @@
         payload_signature: "foo".to_string(),
       }),
       content_upload: Some(Prekey {
-        prekey: "content_prekey".to_string(),
+        prekey: generate_random_olm_key(),
         prekey_signature: "content_prekey_sig".to_string(),
       }),
       notif_upload: Some(Prekey {
-        prekey: "notif_prekey".to_string(),
+        prekey: generate_random_olm_key(),
         prekey_signature: "notif_prekey_sig".to_string(),
       }),
       one_time_content_prekeys: Vec::new(),
@@ -151,11 +152,11 @@
         payload_signature: "foo".to_string(),
       }),
       content_upload: Some(Prekey {
-        prekey: "content_prekey".to_string(),
+        prekey: generate_random_olm_key(),
         prekey_signature: "content_prekey_sig".to_string(),
       }),
       notif_upload: Some(Prekey {
-        prekey: "notif_prekey".to_string(),
+        prekey: generate_random_olm_key(),
         prekey_signature: "notif_prekey_sig".to_string(),
       }),
       one_time_content_prekeys: Vec::new(),
diff --git a/services/commtest/src/identity/olm_account_infos.rs b/services/commtest/src/identity/olm_account_infos.rs
--- a/services/commtest/src/identity/olm_account_infos.rs
+++ b/services/commtest/src/identity/olm_account_infos.rs
@@ -48,7 +48,7 @@
   };
 }
 
-pub fn get_random_otk() -> String {
+pub fn generate_random_olm_key() -> String {
   rand::thread_rng()
     .sample_iter(&Alphanumeric)
     .take(43)
diff --git a/services/commtest/tests/identity_keyserver_tests.rs b/services/commtest/tests/identity_keyserver_tests.rs
--- a/services/commtest/tests/identity_keyserver_tests.rs
+++ b/services/commtest/tests/identity_keyserver_tests.rs
@@ -1,7 +1,7 @@
 use commtest::identity::device::{
   register_user_device, DEVICE_TYPE, PLACEHOLDER_CODE_VERSION,
 };
-use commtest::identity::olm_account_infos::get_random_otk;
+use commtest::identity::olm_account_infos::generate_random_olm_key;
 use commtest::service_addr;
 use grpc_clients::identity::{
   get_auth_client,
@@ -26,8 +26,8 @@
   .await
   .expect("Couldn't connect to identity service");
 
-  let content_one_time_prekey = get_random_otk();
-  let notif_one_time_prekey = get_random_otk();
+  let content_one_time_prekey = generate_random_olm_key();
+  let notif_one_time_prekey = generate_random_olm_key();
 
   let upload_request = UploadOneTimeKeysRequest {
     content_one_time_prekeys: vec![content_one_time_prekey.clone()],
diff --git a/services/commtest/tests/identity_one_time_key_tests.rs b/services/commtest/tests/identity_one_time_key_tests.rs
--- a/services/commtest/tests/identity_one_time_key_tests.rs
+++ b/services/commtest/tests/identity_one_time_key_tests.rs
@@ -1,7 +1,7 @@
 use commtest::identity::device::{
   register_user_device, DEVICE_TYPE, PLACEHOLDER_CODE_VERSION,
 };
-use commtest::identity::olm_account_infos::get_random_otk;
+use commtest::identity::olm_account_infos::generate_random_olm_key;
 use commtest::service_addr;
 use grpc_clients::identity::{
   get_auth_client, protos::authenticated::UploadOneTimeKeysRequest,
@@ -23,8 +23,14 @@
   .expect("Couldn't connect to identity service");
 
   let upload_request = UploadOneTimeKeysRequest {
-    content_one_time_prekeys: vec![get_random_otk(), get_random_otk()],
-    notif_one_time_prekeys: vec![get_random_otk(), get_random_otk()],
+    content_one_time_prekeys: vec![
+      generate_random_olm_key(),
+      generate_random_olm_key(),
+    ],
+    notif_one_time_prekeys: vec![
+      generate_random_olm_key(),
+      generate_random_olm_key(),
+    ],
   };
 
   identity_client
diff --git a/services/commtest/tests/identity_tunnelbroker_tests.rs b/services/commtest/tests/identity_tunnelbroker_tests.rs
--- a/services/commtest/tests/identity_tunnelbroker_tests.rs
+++ b/services/commtest/tests/identity_tunnelbroker_tests.rs
@@ -1,7 +1,7 @@
 use commtest::identity::device::{
   register_user_device, DEVICE_TYPE, PLACEHOLDER_CODE_VERSION,
 };
-use commtest::identity::olm_account_infos::get_random_otk;
+use commtest::identity::olm_account_infos::generate_random_olm_key;
 use commtest::service_addr;
 use commtest::tunnelbroker::socket::{create_socket, receive_message};
 use futures_util::StreamExt;
@@ -48,8 +48,8 @@
   .await
   .expect("Couldn't connect to identity service");
 
-  let content_one_time_prekeys = vec![get_random_otk()];
-  let notif_one_time_prekeys = vec![get_random_otk()];
+  let content_one_time_prekeys = vec![generate_random_olm_key()];
+  let notif_one_time_prekeys = vec![generate_random_olm_key()];
   let upload_request = UploadOneTimeKeysRequest {
     content_one_time_prekeys,
     notif_one_time_prekeys,
diff --git a/services/identity/src/database/device_list.rs b/services/identity/src/database/device_list.rs
--- a/services/identity/src/database/device_list.rs
+++ b/services/identity/src/database/device_list.rs
@@ -26,6 +26,7 @@
   error::{DeviceListError, Error},
   grpc_services::protos::{self, unauth::DeviceType},
   grpc_utils::DeviceKeysInfo,
+  olm::is_valid_olm_key,
 };
 
 use super::DatabaseClient;
@@ -80,8 +81,14 @@
     upload: FlattenedDeviceKeyUpload,
     code_version: u64,
     login_time: DateTime<Utc>,
-  ) -> Self {
-    Self {
+  ) -> Result<Self, Error> {
+    if !is_valid_olm_key(&upload.content_prekey)
+      || !is_valid_olm_key(&upload.notif_prekey)
+    {
+      error!("Invalid prekey format");
+      return Err(Error::InvalidFormat);
+    }
+    let device_row = Self {
       user_id: user_id.into(),
       device_id: upload.device_id_key,
       device_type: DeviceType::from_str_name(upload.device_type.as_str_name())
@@ -100,7 +107,8 @@
       },
       code_version,
       login_time,
-    }
+    };
+    Ok(device_row)
   }
 }
 
@@ -503,6 +511,12 @@
     content_prekey: Prekey,
     notif_prekey: Prekey,
   ) -> Result<(), Error> {
+    if !is_valid_olm_key(&content_prekey.prekey)
+      || !is_valid_olm_key(&notif_prekey.prekey)
+    {
+      error!("Invalid prekey format");
+      return Err(Error::InvalidFormat);
+    }
     self
       .client
       .update_item()
@@ -691,7 +705,7 @@
       device_key_upload,
       code_version,
       login_time,
-    );
+    )?;
     let device_id = new_device.device_id.clone();
 
     self
@@ -735,7 +749,7 @@
           device_key_upload,
           code_version,
           login_time,
-        );
+        )?;
 
         if device_ids.iter().any(|id| &new_device.device_id == id) {
           warn!(