diff --git a/server/texture-sync-server/Cargo.toml b/server/texture-sync-server/Cargo.toml
index a0f5ebd..7b9dcec 100644
--- a/server/texture-sync-server/Cargo.toml
+++ b/server/texture-sync-server/Cargo.toml
@@ -8,4 +8,5 @@ edition = "2018"
 image = "0.21.1"
 serde = { version = "1.0.90", features = ["derive"] }
 serde_json = "1.0.39"
-lovecraft = "0.2.0"
\ No newline at end of file
+sha2 = "0.8.0"
+lovecraft = "0.2.0"
diff --git a/server/texture-sync-server/src/main.rs b/server/texture-sync-server/src/main.rs
index 8938488..098566f 100644
--- a/server/texture-sync-server/src/main.rs
+++ b/server/texture-sync-server/src/main.rs
@@ -11,6 +11,8 @@ extern crate serde_json;
 extern crate image;
 extern crate lovecraft;
 
+extern crate sha2;
+
 pub mod model;
 pub mod persistency;
 pub mod protocol;
diff --git a/server/texture-sync-server/src/persistency/collection_file.rs b/server/texture-sync-server/src/persistency/collection_file.rs
index 960cf80..2277153 100644
--- a/server/texture-sync-server/src/persistency/collection_file.rs
+++ b/server/texture-sync-server/src/persistency/collection_file.rs
@@ -10,9 +10,29 @@ struct CollectionFile {
 }
 
 pub fn load_collection_file(path: &Path) -> io::Result<Vec<Texture>> {
-    let file = fs::File::open(path)?;
-    let buf_reader = io::BufReader::new(file);
+    match fs::File::open(path) {
+        Ok(file) => {
+            let buf_reader = io::BufReader::new(file);
 
-    let collection: CollectionFile = serde_json::from_reader(buf_reader)?;
-    Ok(collection.textures)
+            let collection: CollectionFile = serde_json::from_reader(buf_reader)?;
+            Ok(collection.textures)
+        }
+        Err(e) => {
+            if e.kind() == io::ErrorKind::NotFound {
+                // File has not been created yet.
+                Ok(Vec::new())
+            } else {
+                Err(e)
+            }
+        }
+    }
+}
+
+pub fn store_collection_file(path: &Path, content: &Vec<Texture>) -> io::Result<()> {
+    let collection_file = CollectionFile {
+        textures: content.clone(),
+    };
+    let file = fs::File::create(path)?;
+    serde_json::to_writer(file, &collection_file)?;
+    Ok(())
 }
diff --git a/server/texture-sync-server/src/persistency/mod.rs b/server/texture-sync-server/src/persistency/mod.rs
index 6d430b4..81108f7 100644
--- a/server/texture-sync-server/src/persistency/mod.rs
+++ b/server/texture-sync-server/src/persistency/mod.rs
@@ -11,6 +11,8 @@ use std::io;
 use std::path::{Path, PathBuf};
 use std::sync::Arc;
 
+use sha2::{self, Digest};
+
 pub use self::search::Query;
 mod collection_file;
 mod image_convert;
@@ -31,6 +33,18 @@ pub struct DataStore {
     preview_cache: HashMap<(TextureFormat, Sha256), Arc<Vec<u8>>>,
 }
 
+fn sha256(data: &[u8]) -> Sha256 {
+    let mut hasher = sha2::Sha256::new();
+    hasher.input(data);
+    let hash_result = hasher.result();
+    let hash_slice = hash_result.as_slice();
+    let mut hash_arr = [0u8; 32];
+    for i in 0..32 {
+        hash_arr[i] = hash_slice[i];
+    }
+    Sha256(hash_arr)
+}
+
 impl DataStore {
     pub fn new(path: &Path) -> io::Result<DataStore> {
         let base_path = path.to_path_buf();
@@ -100,6 +114,11 @@ impl DataStore {
                 match data {
                     None => Ok(ReplaceTextureStatus::NeedTextureData(tex.texture_hash)),
                     Some(blob) => {
+                        if sha256(&blob) != tex.texture_hash {
+                            return Err(ProtocolError::BadRequest(
+                                "The texture does not have the given hash value.".to_string(),
+                            ));
+                        }
                         let mut tmp_image_path = self.data_dir.clone();
                         tmp_image_path.push("textures");
                         tmp_image_path.push(format!(
@@ -182,4 +201,13 @@ impl DataStore {
     pub fn get_texture_preview(&mut self, hash: &Sha256) -> TextureFileResult {
         unimplemented!();
     }
+
+    fn store_metadata(&self) -> io::Result<()> {
+        let mut tmp_path = self.data_dir.clone();
+        tmp_path.push("collection_new.json");
+        collection_file::store_collection_file(&tmp_path, &self.texture)?;
+        let mut final_path = self.data_dir.clone();
+        final_path.push("collection.json");
+        fs::rename(tmp_path, final_path)
+    }
 }