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,
 };
@@ -70,11 +71,11 @@
         social_proof: None,
       }),
       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(),
@@ -153,11 +154,11 @@
         social_proof: None,
       }),
       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;
@@ -230,9 +231,17 @@
   }
 }
 
-impl From<DeviceRow> for AttributeMap {
-  fn from(value: DeviceRow) -> Self {
-    HashMap::from([
+impl TryFrom<DeviceRow> for AttributeMap {
+  type Error = Error;
+
+  fn try_from(value: DeviceRow) -> Result<Self, Self::Error> {
+    if !is_valid_olm_key(&value.content_prekey.prekey)
+      || !is_valid_olm_key(&value.notif_prekey.prekey)
+    {
+      error!("Invalid prekey format");
+      return Err(Error::InvalidFormat);
+    }
+    let attribute_map = HashMap::from([
       (ATTR_USER_ID.to_string(), AttributeValue::S(value.user_id)),
       (
         ATTR_ITEM_ID.to_string(),
@@ -257,7 +266,8 @@
         ATTR_LOGIN_TIME.to_string(),
         AttributeValue::S(value.login_time.to_rfc3339()),
       ),
-    ])
+    ]);
+    Ok(attribute_map)
   }
 }
 
@@ -506,6 +516,12 @@
     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()
@@ -701,7 +717,7 @@
       .client
       .put_item()
       .table_name(devices_table::NAME)
-      .set_item(Some(new_device.into()))
+      .set_item(Some(new_device.try_into()?))
       .send()
       .await
       .map_err(|e| {
@@ -757,7 +773,7 @@
         // Put new device
         let put_device = Put::builder()
           .table_name(devices_table::NAME)
-          .set_item(Some(new_device.into()))
+          .set_item(Some(new_device.try_into()?))
           .condition_expression(
             "attribute_not_exists(#user_id) AND attribute_not_exists(#item_id)",
           )