diff --git a/native/native_rust_library/src/backup/upload_handler.rs b/native/native_rust_library/src/backup/upload_handler.rs
index 1bfa4ebfd..fa4dc69cf 100644
--- a/native/native_rust_library/src/backup/upload_handler.rs
+++ b/native/native_rust_library/src/backup/upload_handler.rs
@@ -1,337 +1,344 @@
 use super::file_info::BackupFileInfo;
 use super::get_user_identity_from_secure_store;
 use crate::backup::compaction_upload_promises;
 use crate::constants::BACKUP_SERVICE_CONNECTION_RETRY_DELAY;
 use crate::ffi::{
   get_backup_directory_path, get_backup_file_path, get_backup_log_file_path,
   get_backup_user_keys_file_path, get_siwe_backup_message_path,
 };
 use crate::BACKUP_SOCKET_ADDR;
 use crate::RUNTIME;
 use backup_client::UserIdentity;
 use backup_client::{
   BackupClient, Error as BackupError, LogUploadConfirmation, Stream, StreamExt,
 };
 use backup_client::{BackupData, Sink, UploadLogRequest};
 use lazy_static::lazy_static;
 use std::collections::HashSet;
 use std::convert::Infallible;
 use std::error::Error;
 use std::future::Future;
 use std::io::BufRead;
 use std::io::ErrorKind;
 use std::path::PathBuf;
 use std::pin::Pin;
 use std::sync::{Arc, Mutex};
 use tokio::sync::Notify;
 use tokio::task::JoinHandle;
 
 lazy_static! {
   pub static ref UPLOAD_HANDLER: Arc<Mutex<Option<JoinHandle<Infallible>>>> =
     Arc::new(Mutex::new(None));
   static ref TRIGGER_BACKUP_FILE_UPLOAD: Arc<Notify> = Arc::new(Notify::new());
   static ref BACKUP_FOLDER_PATH: PathBuf = PathBuf::from(
     get_backup_directory_path().expect("Getting backup directory path failed")
   );
 }
 
 pub mod ffi {
   use super::*;
 
   pub fn start_backup_handler() -> Result<(), Box<dyn Error>> {
     let mut handle = UPLOAD_HANDLER.lock()?;
     match handle.take() {
       // Don't start backup handler if it's already running
       Some(handle) if !handle.is_finished() => (),
       _ => {
         *handle = Some(RUNTIME.spawn(super::start()?));
       }
     }
 
     Ok(())
   }
 
   pub fn stop_backup_handler() -> Result<(), Box<dyn Error>> {
     let Some(handler) = UPLOAD_HANDLER.lock()?.take() else {
       return Ok(());
     };
     if handler.is_finished() {
       return Ok(());
     }
 
     handler.abort();
     Ok(())
   }
 
   pub fn trigger_backup_file_upload() {
     TRIGGER_BACKUP_FILE_UPLOAD.notify_one();
   }
 }
 
 pub fn start() -> Result<impl Future<Output = Infallible>, Box<dyn Error>> {
   let backup_client = BackupClient::new(BACKUP_SOCKET_ADDR)?;
   let user_identity = get_user_identity_from_secure_store()?;
 
   Ok(async move {
     loop {
       let (tx, rx) = match backup_client.upload_logs(&user_identity).await {
         Ok(ws) => ws,
         Err(err) => {
           println!(
             "Backup handler error when estabilishing connection: '{err:?}'"
           );
           tokio::time::sleep(BACKUP_SERVICE_CONNECTION_RETRY_DELAY).await;
           continue;
         }
       };
 
       let mut tx = Box::pin(tx);
       let mut rx = Box::pin(rx);
 
       let logs_waiting_for_confirmation = Mutex::new(HashSet::<PathBuf>::new());
 
       loop {
         let err = tokio::select! {
           Err(err) = watch_and_upload_files(&backup_client, &user_identity, &mut tx, &logs_waiting_for_confirmation) => err,
           Err(err) = delete_confirmed_logs(&mut rx, &logs_waiting_for_confirmation) => err,
         };
 
         println!("Backup handler error: '{err:?}'");
         match err {
           BackupHandlerError::BackupError(_)
           | BackupHandlerError::WSClosed
           | BackupHandlerError::LockError => break,
           BackupHandlerError::IoError(_)
           | BackupHandlerError::CxxException(_) => continue,
           BackupHandlerError::FromUtf8Error(_) => break,
         }
       }
 
       tokio::time::sleep(BACKUP_SERVICE_CONNECTION_RETRY_DELAY).await;
       println!("Retrying backup log upload");
     }
   })
 }
 
 async fn watch_and_upload_files(
   backup_client: &BackupClient,
   user_identity: &UserIdentity,
   tx: &mut Pin<Box<impl Sink<UploadLogRequest, Error = BackupError>>>,
   logs_waiting_for_confirmation: &Mutex<HashSet<PathBuf>>,
 ) -> Result<Infallible, BackupHandlerError> {
   loop {
     let mut file_stream = match tokio::fs::read_dir(&*BACKUP_FOLDER_PATH).await
     {
       Ok(file_stream) => file_stream,
       Err(err) if err.kind() == ErrorKind::NotFound => {
         TRIGGER_BACKUP_FILE_UPLOAD.notified().await;
         continue;
       }
       Err(err) => return Err(err.into()),
     };
 
     while let Some(file) = file_stream.next_entry().await? {
       let path = file.path();
 
       if logs_waiting_for_confirmation.lock()?.contains(&path) {
         continue;
       }
 
       let Ok(BackupFileInfo {
         backup_id,
         log_id,
         additional_data,
       }) = path.clone().try_into()
       else {
         continue;
       };
 
       // Skip additional data files (attachments, user keys). They will be
       // handled when we iterate over the corresponding files with the
       // main content
       if additional_data.is_some() {
         continue;
       }
 
       if let Some(log_id) = log_id {
         log::upload_files(tx, backup_id, log_id).await?;
         logs_waiting_for_confirmation.lock()?.insert(path);
       } else {
         compaction::upload_files(backup_client, user_identity, backup_id)
           .await?;
       }
     }
 
     TRIGGER_BACKUP_FILE_UPLOAD.notified().await;
   }
 }
 
 async fn delete_confirmed_logs(
   rx: &mut Pin<
     Box<impl Stream<Item = Result<LogUploadConfirmation, BackupError>>>,
   >,
   logs_waiting_for_confirmation: &Mutex<HashSet<PathBuf>>,
 ) -> Result<Infallible, BackupHandlerError> {
   while let Some(LogUploadConfirmation { backup_id, log_id }) =
     rx.next().await.transpose()?
   {
     let path =
       get_backup_log_file_path(&backup_id, &log_id.to_string(), false)?;
     logs_waiting_for_confirmation
       .lock()?
       .remove(&PathBuf::from(path));
 
     tokio::spawn(log::cleanup_files(backup_id, log_id));
   }
 
   Err(BackupHandlerError::WSClosed)
 }
 
 pub mod compaction {
   use super::*;
 
   pub async fn upload_files(
     backup_client: &BackupClient,
     user_identity: &UserIdentity,
     backup_id: String,
   ) -> Result<(), BackupHandlerError> {
     let user_data_path = get_backup_file_path(&backup_id, false)?;
-    let user_data = tokio::fs::read(&user_data_path).await?;
-
+    let user_data = match tokio::fs::read(&user_data_path).await {
+      Ok(data) => Some(data),
+      Err(err) if err.kind() == ErrorKind::NotFound => None,
+      Err(err) => return Err(err.into()),
+    };
     let user_keys_path = get_backup_user_keys_file_path(&backup_id)?;
-    let user_keys = tokio::fs::read(&user_keys_path).await?;
+    let user_keys = match tokio::fs::read(&user_keys_path).await {
+      Ok(data) => Some(data),
+      Err(err) if err.kind() == ErrorKind::NotFound => None,
+      Err(err) => return Err(err.into()),
+    };
 
     let attachments_path = get_backup_file_path(&backup_id, true)?;
     let attachments = match tokio::fs::read(&attachments_path).await {
       Ok(data) => data.lines().collect::<Result<_, _>>()?,
       Err(err) if err.kind() == ErrorKind::NotFound => Vec::new(),
       Err(err) => return Err(err.into()),
     };
 
     let siwe_backup_msg_path = get_siwe_backup_message_path(&backup_id)?;
     let siwe_backup_msg = match tokio::fs::read(&siwe_backup_msg_path).await {
       Ok(data) => match String::from_utf8(data) {
         Ok(valid_string) => Some(valid_string),
         Err(err) => return Err(err.into()),
       },
       Err(err) if err.kind() == ErrorKind::NotFound => None,
       Err(err) => return Err(err.into()),
     };
 
     let backup_data = BackupData {
       backup_id: backup_id.clone(),
       user_data,
       user_keys,
       attachments,
       siwe_backup_msg,
     };
 
     backup_client
       .upload_backup(user_identity, backup_data)
       .await?;
 
     compaction_upload_promises::resolve(&backup_id, Ok(()));
     tokio::spawn(cleanup_files(backup_id));
 
     Ok(())
   }
 
   pub async fn cleanup_files(backup_id: String) {
     let backup_files_cleanup = async {
       let user_data_path = get_backup_file_path(&backup_id, false)?;
       tokio::fs::remove_file(&user_data_path).await?;
       let user_keys_path = get_backup_user_keys_file_path(&backup_id)?;
       tokio::fs::remove_file(&user_keys_path).await?;
       let attachments_path = get_backup_file_path(&backup_id, true)?;
       match tokio::fs::remove_file(&attachments_path).await {
         Ok(()) => Result::<_, Box<dyn Error>>::Ok(()),
         Err(err) if err.kind() == ErrorKind::NotFound => Ok(()),
         Err(err) => Err(err.into()),
       }?;
       let siwe_backup_msg_path = get_siwe_backup_message_path(&backup_id)?;
       match tokio::fs::remove_file(&siwe_backup_msg_path).await {
         Ok(()) => Result::<_, Box<dyn Error>>::Ok(()),
         Err(err) if err.kind() == ErrorKind::NotFound => Ok(()),
         Err(err) => Err(err.into()),
       }
     };
 
     if let Err(err) = backup_files_cleanup.await {
       println!("Error when cleaning up the backup files: {err:?}");
     }
   }
 }
 
 mod log {
   use backup_client::SinkExt;
 
   use super::*;
 
   pub async fn upload_files(
     tx: &mut Pin<Box<impl Sink<UploadLogRequest, Error = BackupError>>>,
     backup_id: String,
     log_id: usize,
   ) -> Result<(), BackupHandlerError> {
     let log_id_string = log_id.to_string();
     let content_path =
       get_backup_log_file_path(&backup_id, &log_id_string, false)?;
     let content = tokio::fs::read(&content_path).await?;
 
     let attachments_path =
       get_backup_log_file_path(&backup_id, &log_id_string, true)?;
     let attachments = match tokio::fs::read(&attachments_path).await {
       Ok(data) => Some(data.lines().collect::<Result<_, _>>()?),
       Err(err) if err.kind() == ErrorKind::NotFound => None,
       Err(err) => return Err(err.into()),
     };
 
     let log_data = UploadLogRequest {
       backup_id,
       log_id,
       content,
       attachments,
     };
     tx.send(log_data.clone()).await?;
 
     Ok(())
   }
 
   pub async fn cleanup_files(backup_id: String, log_id: usize) {
     let backup_files_cleanup = async {
       let log_id = log_id.to_string();
 
       let path = get_backup_log_file_path(&backup_id, &log_id, false)?;
       tokio::fs::remove_file(&path).await?;
 
       let attachments_path =
         get_backup_log_file_path(&backup_id, &log_id, true)?;
       match tokio::fs::remove_file(&attachments_path).await {
         Ok(()) => Result::<_, Box<dyn Error>>::Ok(()),
         Err(err) if err.kind() == ErrorKind::NotFound => Ok(()),
         Err(err) => Err(err.into()),
       }
     };
 
     if let Err(err) = backup_files_cleanup.await {
       println!("{err:?}");
     }
   }
 }
 
 #[derive(
   Debug, derive_more::Display, derive_more::From, derive_more::Error,
 )]
 pub enum BackupHandlerError {
   BackupError(BackupError),
   WSClosed,
   IoError(std::io::Error),
   CxxException(cxx::Exception),
   LockError,
   FromUtf8Error(std::string::FromUtf8Error),
 }
 
 impl<T> From<std::sync::PoisonError<T>> for BackupHandlerError {
   fn from(_: std::sync::PoisonError<T>) -> Self {
     Self::LockError
   }
 }
diff --git a/services/commtest/src/backup/backup_utils.rs b/services/commtest/src/backup/backup_utils.rs
index 964661ac2..4dcef9e5a 100644
--- a/services/commtest/src/backup/backup_utils.rs
+++ b/services/commtest/src/backup/backup_utils.rs
@@ -1,97 +1,97 @@
 use crate::identity::device::DeviceInfo;
 
 use crate::tools::generate_stable_nbytes;
 use backup_client::{BackupData, Error as BackupClientError};
 use bytesize::ByteSize;
 use comm_lib::auth::UserIdentity;
 use comm_lib::backup::UploadLogRequest;
 use reqwest::StatusCode;
 use uuid::Uuid;
 
 pub fn generate_backup_data(predefined_byte_value: u8) -> BackupData {
   BackupData {
     backup_id: Uuid::new_v4().to_string(),
-    user_keys: generate_stable_nbytes(
+    user_keys: Some(generate_stable_nbytes(
       ByteSize::kib(4).as_u64() as usize,
       Some(predefined_byte_value),
-    ),
-    user_data: generate_stable_nbytes(
+    )),
+    user_data: Some(generate_stable_nbytes(
       ByteSize::mib(4).as_u64() as usize,
       Some(predefined_byte_value),
-    ),
+    )),
     attachments: vec![],
     siwe_backup_msg: None,
   }
 }
 
 fn generate_log_data(backup_id: &str, value: u8) -> Vec<UploadLogRequest> {
   const IN_DB_SIZE: usize = ByteSize::kib(4).as_u64() as usize;
   const IN_BLOB_SIZE: usize = ByteSize::kib(400).as_u64() as usize;
 
   (1..30)
     .map(|log_id| {
       let size = if log_id % 2 == 0 {
         IN_DB_SIZE
       } else {
         IN_BLOB_SIZE
       };
       let attachments = if log_id % 10 == 0 {
         Some(vec![Uuid::new_v4().to_string()])
       } else {
         None
       };
       let mut content = generate_stable_nbytes(size, Some(value));
       let unique_suffix = log_id.to_string();
       content.extend(unique_suffix.as_bytes());
 
       UploadLogRequest {
         backup_id: backup_id.to_string(),
         log_id,
         content,
         attachments,
       }
     })
     .collect()
 }
 
 pub fn generate_backup_data_with_logs(
   predefined_byte_values: Vec<u8>,
 ) -> Vec<(BackupData, Vec<UploadLogRequest>)> {
   predefined_byte_values
     .into_iter()
     .map(|byte_value| {
       let backup_data = generate_backup_data(byte_value);
       let log_data = generate_log_data(&backup_data.backup_id, byte_value);
       (backup_data, log_data)
     })
     .collect()
 }
 
 pub fn assert_reqwest_error<T>(
   response: Result<T, BackupClientError>,
   expected_status: StatusCode,
 ) {
   match response {
     Err(BackupClientError::ReqwestError(error)) => {
       assert_eq!(
         error.status(),
         Some(expected_status),
         "Expected status {}",
         expected_status
       );
     }
     Err(err) => panic!(
       "Backup should return ReqwestError, instead got response: {:?}",
       err
     ),
     Ok(_) => panic!("Backup should return BackupClientError"),
   }
 }
 
 pub fn create_user_identity(device_info: DeviceInfo) -> UserIdentity {
   UserIdentity {
     user_id: device_info.user_id.clone(),
     access_token: device_info.access_token.clone(),
     device_id: device_info.device_id.clone(),
   }
 }
diff --git a/services/commtest/tests/backup_integration_test.rs b/services/commtest/tests/backup_integration_test.rs
index c77533f69..e5f2d3de6 100644
--- a/services/commtest/tests/backup_integration_test.rs
+++ b/services/commtest/tests/backup_integration_test.rs
@@ -1,140 +1,140 @@
 use backup_client::{
   BackupClient, BackupDescriptor, DownloadedLog, LogUploadConfirmation,
   RequestedData, SinkExt, StreamExt, TryStreamExt,
 };
 use comm_lib::backup::LatestBackupInfoResponse;
 use commtest::backup::backup_utils::{
   assert_reqwest_error, create_user_identity, generate_backup_data_with_logs,
 };
 use commtest::identity::device::register_user_device;
 use commtest::{service_addr, tools::Error};
 use grpc_clients::identity::DeviceType;
 use reqwest::StatusCode;
 use std::collections::HashSet;
 
 #[tokio::test]
 async fn backup_integration_test() -> Result<(), Error> {
   let backup_client = BackupClient::new(service_addr::BACKUP_SERVICE_HTTP)?;
 
   let device_info = register_user_device(None, Some(DeviceType::Ios)).await;
   let user_identity = create_user_identity(device_info.clone());
 
   let backup_datas = generate_backup_data_with_logs(vec![b'a', b'b']);
 
   // Upload backups
   for (backup_data, log_datas) in &backup_datas {
     backup_client
       .upload_backup(&user_identity, backup_data.clone())
       .await?;
 
     let (mut tx, rx) = backup_client.upload_logs(&user_identity).await?;
 
     for log_data in log_datas {
       tx.send(log_data.clone()).await?;
     }
 
     let result: HashSet<LogUploadConfirmation> =
       rx.take(log_datas.len()).try_collect().await?;
     let expected = log_datas
       .iter()
       .map(|data| LogUploadConfirmation {
         backup_id: data.backup_id.clone(),
         log_id: data.log_id,
       })
       .collect();
 
     assert_eq!(result, expected);
   }
 
   // Test direct lookup
   let (backup_data, log_datas) = &backup_datas[1];
 
   let second_backup_descriptor = BackupDescriptor::BackupID {
     backup_id: backup_data.backup_id.clone(),
     user_identity: user_identity.clone(),
   };
 
   let user_keys = backup_client
     .download_backup_data(&second_backup_descriptor, RequestedData::UserKeys)
     .await?;
-  assert_eq!(user_keys, backup_data.user_keys);
+  assert_eq!(Some(user_keys), backup_data.user_keys);
 
   let user_data = backup_client
     .download_backup_data(&second_backup_descriptor, RequestedData::UserData)
     .await?;
-  assert_eq!(user_data, backup_data.user_data);
+  assert_eq!(Some(user_data), backup_data.user_data);
 
   // Test latest backup lookup for nonexistent user
   let latest_backup_descriptor = BackupDescriptor::Latest {
     user_identifier: "nonexistent_user".to_string(),
   };
 
   let nonexistent_user_response = backup_client
     .download_backup_data(&latest_backup_descriptor, RequestedData::BackupInfo)
     .await;
 
   assert_reqwest_error(nonexistent_user_response, StatusCode::BAD_REQUEST);
 
   // Test latest backup lookup
   let latest_backup_descriptor = BackupDescriptor::Latest {
     user_identifier: device_info.username,
   };
 
   let backup_info_response = backup_client
     .download_backup_data(&latest_backup_descriptor, RequestedData::BackupInfo)
     .await?;
   let response: LatestBackupInfoResponse =
     serde_json::from_slice(&backup_info_response)?;
   assert_eq!(response.backup_id, backup_data.backup_id);
   assert_eq!(response.user_id, device_info.user_id);
 
   let user_keys = backup_client
     .download_backup_data(&latest_backup_descriptor, RequestedData::UserKeys)
     .await?;
-  assert_eq!(user_keys, backup_data.user_keys);
+  assert_eq!(Some(user_keys), backup_data.user_keys);
 
   // Test log download
   let log_stream = backup_client
     .download_logs(&user_identity, &backup_data.backup_id)
     .await;
 
   let downloaded_logs: Vec<DownloadedLog> = log_stream.try_collect().await?;
 
   let expected_logs: Vec<DownloadedLog> = log_datas
     .iter()
     .map(|data| DownloadedLog {
       content: data.content.clone(),
       attachments: data.attachments.clone(),
     })
     .collect();
   assert_eq!(downloaded_logs, expected_logs);
 
   // Test backup cleanup
   let (removed_backup, _) = &backup_datas[0];
   let removed_backup_descriptor = BackupDescriptor::BackupID {
     backup_id: removed_backup.backup_id.clone(),
     user_identity: user_identity.clone(),
   };
 
   let response = backup_client
     .download_backup_data(&removed_backup_descriptor, RequestedData::UserKeys)
     .await;
 
   assert_reqwest_error(response, StatusCode::NOT_FOUND);
 
   // Test log cleanup
   let log_stream = backup_client
     .download_logs(&user_identity, &removed_backup.backup_id)
     .await;
 
   let downloaded_logs: Vec<DownloadedLog> = log_stream.try_collect().await?;
 
   if !downloaded_logs.is_empty() {
     panic!(
       "Logs for first backup should have been removed, \
       instead got: {downloaded_logs:?}"
     )
   }
 
   Ok(())
 }
diff --git a/services/commtest/tests/backup_performance_test.rs b/services/commtest/tests/backup_performance_test.rs
index 98f84d109..bdd5daa54 100644
--- a/services/commtest/tests/backup_performance_test.rs
+++ b/services/commtest/tests/backup_performance_test.rs
@@ -1,169 +1,169 @@
 use backup_client::{BackupClient, BackupDescriptor, RequestedData};
 
 use comm_lib::backup::LatestBackupInfoResponse;
 use commtest::backup::backup_utils::{
   create_user_identity, generate_backup_data,
 };
 use commtest::identity::device::register_user_device;
 use commtest::{
   service_addr,
   tools::{obtain_number_of_threads, Error},
 };
 use grpc_clients::identity::DeviceType;
 use tokio::{runtime::Runtime, task::JoinSet};
 
 #[tokio::test]
 async fn backup_performance_test() -> Result<(), Error> {
   let backup_client = BackupClient::new(service_addr::BACKUP_SERVICE_HTTP)?;
 
   let number_of_threads = obtain_number_of_threads();
 
   let rt = Runtime::new().unwrap();
 
   println!(
     "Running performance tests for backup, number of threads: {}",
     number_of_threads
   );
 
   let backup_data: Vec<_> = (0..number_of_threads)
     .map(|i| generate_backup_data(i as u8))
     .collect();
 
   let device_info_1 = register_user_device(None, Some(DeviceType::Ios)).await;
   let device_info_2 = register_user_device(None, Some(DeviceType::Ios)).await;
 
   let user_identities = [
     create_user_identity(device_info_1.clone()),
     create_user_identity(device_info_2.clone()),
   ];
 
   tokio::task::spawn_blocking(move || {
     println!("Creating new backups");
     rt.block_on(async {
       let mut set = JoinSet::new();
       for (i, item) in backup_data.iter().cloned().enumerate() {
         let backup_client = backup_client.clone();
         let user = user_identities[i % user_identities.len()].clone();
 
         set.spawn(async move {
           backup_client.upload_backup(&user, item).await.unwrap();
         });
       }
 
       while let Some(result) = set.join_next().await {
         result.unwrap();
       }
     });
 
     let mut latest_ids_for_user = vec![];
     println!("Reading latest ids");
     rt.block_on(async {
       let mut handlers = vec![];
       for user in &user_identities {
         let backup_client = backup_client.clone();
 
         let user_identifier = if user.user_id == device_info_1.user_id {
           device_info_1.username.clone()
         } else {
           device_info_2.username.clone()
         };
 
         let descriptor = BackupDescriptor::Latest { user_identifier };
 
         handlers.push(tokio::spawn(async move {
           let response = backup_client
             .download_backup_data(&descriptor, RequestedData::BackupInfo)
             .await
             .unwrap();
 
           serde_json::from_slice::<LatestBackupInfoResponse>(&response).unwrap()
         }));
       }
 
       for handler in handlers {
         latest_ids_for_user.push(handler.await.unwrap().backup_id);
       }
     });
 
     assert_eq!(latest_ids_for_user.len(), user_identities.len());
 
     let mut latest_user_keys_for_user = vec![];
     println!("Reading latest user keys");
     rt.block_on(async {
       let mut handlers = vec![];
       for user in &user_identities {
         let backup_client = backup_client.clone();
 
         let user_identifier = if user.user_id == device_info_1.user_id {
           device_info_1.username.clone()
         } else {
           device_info_2.username.clone()
         };
 
         let descriptor = BackupDescriptor::Latest { user_identifier };
 
         handlers.push(tokio::spawn(async move {
           backup_client
             .download_backup_data(&descriptor, RequestedData::UserKeys)
             .await
             .unwrap()
         }));
       }
 
       for handler in handlers {
         latest_user_keys_for_user.push(handler.await.unwrap());
       }
     });
 
     assert_eq!(latest_user_keys_for_user.len(), user_identities.len());
     for (backup_id, user_keys) in
       latest_ids_for_user.iter().zip(latest_user_keys_for_user)
     {
       let backup = backup_data
         .iter()
         .find(|data| data.backup_id == *backup_id)
         .expect("Request should return existing backup data");
 
-      assert_eq!(backup.user_keys, user_keys);
+      assert_eq!(backup.user_keys, Some(user_keys));
     }
 
     let mut latest_user_data_for_user = vec![];
     println!("Reading latest user data");
     rt.block_on(async {
       let mut handlers = vec![];
       for (i, backup_id) in latest_ids_for_user.iter().enumerate() {
         let backup_client = backup_client.clone();
         let descriptor = BackupDescriptor::BackupID {
           backup_id: backup_id.clone(),
           user_identity: user_identities[i % user_identities.len()].clone(),
         };
         handlers.push(tokio::spawn(async move {
           backup_client
             .download_backup_data(&descriptor, RequestedData::UserData)
             .await
             .unwrap()
         }));
       }
 
       for handler in handlers {
         latest_user_data_for_user.push(handler.await.unwrap());
       }
     });
 
     assert_eq!(latest_user_data_for_user.len(), user_identities.len());
     for (backup_id, user_data) in
       latest_ids_for_user.iter().zip(latest_user_data_for_user)
     {
       let backup = backup_data
         .iter()
         .find(|data| data.backup_id == *backup_id)
         .expect("Request should return existing backup data");
 
-      assert_eq!(backup.user_data, user_data);
+      assert_eq!(backup.user_data, Some(user_data));
     }
   })
   .await
   .expect("Task panicked");
 
   Ok(())
 }
diff --git a/shared/backup_client/src/lib.rs b/shared/backup_client/src/lib.rs
index a07f94728..2d971e9d8 100644
--- a/shared/backup_client/src/lib.rs
+++ b/shared/backup_client/src/lib.rs
@@ -1,385 +1,401 @@
 #[cfg(target_arch = "wasm32")]
 mod web;
 
 use async_stream::{stream, try_stream};
 pub use comm_lib::auth::UserIdentity;
 pub use comm_lib::backup::{
   DownloadLogsRequest, LatestBackupInfoResponse, LogWSRequest, LogWSResponse,
   UploadLogRequest,
 };
 pub use futures_util::{Sink, SinkExt, Stream, StreamExt, TryStreamExt};
 use hex::ToHex;
 use reqwest::{
   header::InvalidHeaderValue,
   multipart::{Form, Part},
   Body,
 };
 use serde::{Deserialize, Serialize};
 use sha2::{Digest, Sha256};
 use std::time::Duration;
 use tokio_tungstenite_wasm::{
   connect, Error as TungsteniteError, Message::Binary,
 };
 
 const LOG_DOWNLOAD_RETRY_DELAY: Duration = Duration::from_secs(5);
 const LOG_DOWNLOAD_MAX_RETRY: usize = 3;
 
 #[cfg(target_arch = "wasm32")]
 use wasm_bindgen::prelude::wasm_bindgen;
 
 #[cfg_attr(target_arch = "wasm32", wasm_bindgen)]
 #[derive(Debug, Clone)]
 pub struct BackupClient {
   url: reqwest::Url,
 }
 
 impl BackupClient {
   pub fn new<T: TryInto<reqwest::Url>>(url: T) -> Result<Self, T::Error> {
     Ok(BackupClient {
       url: url.try_into()?,
     })
   }
 }
 
 /// Backup functions
 impl BackupClient {
   pub async fn upload_backup(
     &self,
     user_identity: &UserIdentity,
     backup_data: BackupData,
   ) -> Result<(), Error> {
     let BackupData {
       backup_id,
       user_keys,
       user_data,
       attachments,
       siwe_backup_msg,
     } = backup_data;
 
+    let endpoint = match (user_data.clone(), user_keys.clone()) {
+      (None, None) => return Err(Error::InvalidRequest),
+      (Some(_), Some(_)) => "backups",
+      (Some(_), None) => "backups/user_data",
+      (None, Some(_)) => "backups/user_keys",
+    };
+
     let client = reqwest::Client::new();
-    let mut form = Form::new()
-      .text("backup_id", backup_id)
-      .text(
-        "user_keys_hash",
-        Sha256::digest(&user_keys).encode_hex::<String>(),
-      )
-      .part("user_keys", Part::stream(Body::from(user_keys)))
-      .text(
-        "user_data_hash",
-        Sha256::digest(&user_data).encode_hex::<String>(),
-      )
-      .part("user_data", Part::stream(Body::from(user_data)))
-      .text("attachments", attachments.join("\n"));
+    let mut form = Form::new().text("backup_id", backup_id);
+
+    if let Some(user_keys_value) = user_keys.clone() {
+      form = form
+        .text(
+          "user_keys_hash",
+          Sha256::digest(&user_keys_value).encode_hex::<String>(),
+        )
+        .part("user_keys", Part::stream(Body::from(user_keys_value)));
+    }
+
+    if let Some(user_data_value) = user_data.clone() {
+      form = form
+        .text(
+          "user_data_hash",
+          Sha256::digest(&user_data_value).encode_hex::<String>(),
+        )
+        .part("user_data", Part::stream(Body::from(user_data_value)));
+    }
+
+    form = form.text("attachments", attachments.join("\n"));
 
     if let Some(siwe_backup_msg_value) = siwe_backup_msg {
       form = form.text("siwe_backup_msg", siwe_backup_msg_value);
     }
 
     let response = client
-      .post(self.url.join("backups")?)
+      .post(self.url.join(endpoint)?)
       .bearer_auth(user_identity.as_authorization_token()?)
       .multipart(form)
       .send()
       .await?;
 
     response.error_for_status()?;
 
     Ok(())
   }
 
   pub async fn download_backup_data(
     &self,
     backup_descriptor: &BackupDescriptor,
     requested_data: RequestedData,
   ) -> Result<Vec<u8>, Error> {
     let client = reqwest::Client::new();
     let url = self.url.join("backups/")?;
     let url = match backup_descriptor {
       BackupDescriptor::BackupID { backup_id, .. } => {
         url.join(&format!("{backup_id}/"))?
       }
       BackupDescriptor::Latest { user_identifier } => {
         url.join(&format!("latest/{user_identifier}/"))?
       }
     };
     let url = match &requested_data {
       RequestedData::BackupInfo => url.join("backup_info")?,
       RequestedData::UserKeys => url.join("user_keys")?,
       RequestedData::UserData => url.join("user_data")?,
     };
 
     let mut request = client.get(url);
 
     if let BackupDescriptor::BackupID { user_identity, .. } = backup_descriptor
     {
       request = request.bearer_auth(user_identity.as_authorization_token()?)
     }
 
     let response = request.send().await?;
 
     let result = response.error_for_status()?.bytes().await?.to_vec();
 
     Ok(result)
   }
 }
 
 /// Log functions
 impl BackupClient {
   pub async fn upload_logs(
     &self,
     user_identity: &UserIdentity,
   ) -> Result<
     (
       impl Sink<UploadLogRequest, Error = Error>,
       impl Stream<Item = Result<LogUploadConfirmation, Error>>,
     ),
     Error,
   > {
     let (tx, rx) = self.create_log_ws_connection(user_identity).await?;
 
     let rx = rx.map(|response| match response? {
       LogWSResponse::LogUploaded { backup_id, log_id } => {
         Ok(LogUploadConfirmation { backup_id, log_id })
       }
       LogWSResponse::ServerError => Err(Error::ServerError),
       msg => Err(Error::InvalidBackupMessage(msg)),
     });
 
     Ok((tx, rx))
   }
 
   /// Handles complete log download.
   /// It will try and retry download a few times, but if the issues persist
   /// the next item returned will be the last received error and the stream
   /// will be closed.
   pub async fn download_logs<'this>(
     &'this self,
     user_identity: &'this UserIdentity,
     backup_id: &'this str,
   ) -> impl Stream<Item = Result<DownloadedLog, Error>> + 'this {
     stream! {
       let mut last_downloaded_log = None;
       let mut fail_count = 0;
 
       'retry: loop {
         let stream = self.log_download_stream(user_identity, backup_id, &mut last_downloaded_log).await;
         let mut stream = Box::pin(stream);
 
         while let Some(item) = stream.next().await {
           match item {
             Ok(log) => yield Ok(log),
             Err(err) => {
               println!("Error when downloading logs: {err:?}");
 
               fail_count += 1;
               if fail_count >= LOG_DOWNLOAD_MAX_RETRY {
                 yield Err(err);
                 break 'retry;
               }
 
               #[cfg(target_arch = "wasm32")]
               let _ = web::sleep(LOG_DOWNLOAD_RETRY_DELAY).await;
               #[cfg(not(target_arch = "wasm32"))]
               tokio::time::sleep(LOG_DOWNLOAD_RETRY_DELAY).await;
               continue 'retry;
             }
           }
         }
 
         // Everything downloaded
         return;
       }
 
       println!("Log download failed!");
     }
   }
 
   /// Handles singular connection websocket connection. Returns error in case
   /// anything goes wrong e.g. missing log or connection error.
   async fn log_download_stream<'stream>(
     &'stream self,
     user_identity: &'stream UserIdentity,
     backup_id: &'stream str,
     last_downloaded_log: &'stream mut Option<usize>,
   ) -> impl Stream<Item = Result<DownloadedLog, Error>> + 'stream {
     try_stream! {
       let (mut tx, mut rx) = self.create_log_ws_connection(user_identity).await?;
 
       tx.send(DownloadLogsRequest {
         backup_id: backup_id.to_string(),
         from_id: *last_downloaded_log,
       })
       .await?;
 
       while let Some(response) = rx.try_next().await? {
         let expected_log_id = last_downloaded_log.unwrap_or(0);
         match response {
           LogWSResponse::LogDownload {
             content,
             attachments,
             log_id,
           } if log_id == expected_log_id + 1 => {
             *last_downloaded_log = Some(log_id);
             yield DownloadedLog {
               content,
               attachments,
             };
           }
           LogWSResponse::LogDownload { .. } => {
             Err(Error::LogMissing)?;
           }
           LogWSResponse::LogDownloadFinished {
             last_log_id: Some(log_id),
           } if log_id == expected_log_id => {
             tx.send(DownloadLogsRequest {
               backup_id: backup_id.to_string(),
               from_id: *last_downloaded_log,
             })
             .await?
           }
           LogWSResponse::LogDownloadFinished { last_log_id: None } => return,
           LogWSResponse::LogDownloadFinished { .. } => {
             Err(Error::LogMissing)?;
           }
           msg => Err(Error::InvalidBackupMessage(msg))?,
         }
       }
 
       Err(Error::WSClosed)?;
     }
   }
 
   async fn create_log_ws_connection<Request: Into<LogWSRequest>>(
     &self,
     user_identity: &UserIdentity,
   ) -> Result<
     (
       impl Sink<Request, Error = Error>,
       impl Stream<Item = Result<LogWSResponse, Error>>,
     ),
     Error,
   > {
     let url = self.create_ws_url()?;
     let stream = connect(url).await?;
 
     let (mut tx, rx) = stream.split();
 
     tx.send(Binary(bincode::serialize(&LogWSRequest::Authenticate(
       user_identity.clone(),
     ))?))
     .await?;
 
     let tx = tx.with(|request: Request| async {
       let request: LogWSRequest = request.into();
       let request = bincode::serialize(&request)?;
       Ok(Binary(request))
     });
 
     let rx = rx.filter_map(|msg| async {
       let bytes = match msg {
         Ok(Binary(bytes)) => bytes,
         Ok(_) => return Some(Err(Error::InvalidWSMessage)),
         Err(err) => return Some(Err(err.into())),
       };
 
       match bincode::deserialize(&bytes) {
         Ok(response) => Some(Ok(response)),
         Err(err) => Some(Err(err.into())),
       }
     });
 
     let tx = Box::pin(tx);
     let mut rx = Box::pin(rx);
 
     if let Some(response) = rx.try_next().await? {
       match response {
         LogWSResponse::AuthSuccess => {}
         LogWSResponse::Unauthenticated => Err(Error::Unauthenticated)?,
         msg => Err(Error::InvalidBackupMessage(msg))?,
       }
     }
 
     Ok((tx, rx))
   }
 
   fn create_ws_url(&self) -> Result<reqwest::Url, Error> {
     let mut url = self.url.clone();
 
     match url.scheme() {
       "http" => url.set_scheme("ws").map_err(|_| Error::UrlSchemaError)?,
       "https" => url.set_scheme("wss").map_err(|_| Error::UrlSchemaError)?,
       _ => (),
     };
     let url = url.join("logs")?;
 
     Ok(url)
   }
 }
 
 #[derive(Debug, Clone)]
 pub struct BackupData {
   pub backup_id: String,
-  pub user_keys: Vec<u8>,
-  pub user_data: Vec<u8>,
+  pub user_keys: Option<Vec<u8>>,
+  pub user_data: Option<Vec<u8>>,
   pub attachments: Vec<String>,
   pub siwe_backup_msg: Option<String>,
 }
 
 #[derive(Debug, Clone, Serialize, Deserialize)]
 #[serde(tag = "type")]
 pub enum BackupDescriptor {
   BackupID {
     #[serde(rename = "backupID")]
     backup_id: String,
     #[serde(rename = "userIdentity")]
     user_identity: UserIdentity,
   },
   Latest {
     user_identifier: String,
   },
 }
 
 #[cfg_attr(target_arch = "wasm32", wasm_bindgen)]
 #[derive(Debug, Clone)]
 pub enum RequestedData {
   BackupInfo,
   UserKeys,
   UserData,
 }
 
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub struct LogUploadConfirmation {
   pub backup_id: String,
   pub log_id: usize,
 }
 
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub struct DownloadedLog {
   pub content: Vec<u8>,
   pub attachments: Option<Vec<String>>,
 }
 
 #[derive(Debug, derive_more::Display, derive_more::From)]
 pub enum Error {
   InvalidAuthorizationHeader,
   UrlSchemaError,
   UrlError(url::ParseError),
   ReqwestError(reqwest::Error),
   TungsteniteError(TungsteniteError),
   JsonError(serde_json::Error),
   BincodeError(bincode::Error),
   InvalidWSMessage,
   #[display(fmt = "Error::InvalidBackupMessage({:?})", _0)]
   InvalidBackupMessage(LogWSResponse),
   ServerError,
   LogMissing,
   WSClosed,
   Unauthenticated,
+  InvalidRequest,
 }
 impl std::error::Error for Error {}
 
 impl From<InvalidHeaderValue> for Error {
   fn from(_: InvalidHeaderValue) -> Self {
     Self::InvalidAuthorizationHeader
   }
 }