diff --git a/.idea/inspectionProfiles/Project_Default.xml b/.idea/inspectionProfiles/Project_Default.xml
deleted file mode 100644
index 786a0ea..0000000
--- a/.idea/inspectionProfiles/Project_Default.xml
+++ /dev/null
@@ -1,15 +0,0 @@
-<component name="InspectionProjectProfileManager">
-  <profile version="1.0">
-    <option name="myName" value="Project Default" />
-    <inspection_tool class="NullableProblems" enabled="false" level="WARNING" enabled_by_default="false">
-      <option name="REPORT_NULLABLE_METHOD_OVERRIDES_NOTNULL" value="true" />
-      <option name="REPORT_NOT_ANNOTATED_METHOD_OVERRIDES_NOTNULL" value="true" />
-      <option name="REPORT_NOTNULL_PARAMETER_OVERRIDES_NULLABLE" value="true" />
-      <option name="REPORT_NOT_ANNOTATED_PARAMETER_OVERRIDES_NOTNULL" value="true" />
-      <option name="REPORT_NOT_ANNOTATED_GETTER" value="true" />
-      <option name="REPORT_NOT_ANNOTATED_SETTER_PARAMETER" value="true" />
-      <option name="REPORT_ANNOTATION_NOT_PROPAGATED_TO_OVERRIDERS" value="true" />
-      <option name="REPORT_NULLS_PASSED_TO_NON_ANNOTATED_METHOD" value="true" />
-    </inspection_tool>
-  </profile>
-</component>
\ No newline at end of file
diff --git a/.idea/misc.xml b/.idea/misc.xml
index 10467e7..08f9851 100644
--- a/.idea/misc.xml
+++ b/.idea/misc.xml
@@ -1,6 +1,12 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
+  <component name="JavadocGenerationManager">
+    <option name="OUTPUT_DIRECTORY" value="$PROJECT_DIR$/.." />
+  </component>
   <component name="ProjectRootManager" version="2" languageLevel="JDK_1_7" project-jdk-name="1.8" project-jdk-type="JavaSDK">
     <output url="file://$PROJECT_DIR$/build/classes" />
   </component>
+  <component name="ProjectType">
+    <option name="id" value="Android" />
+  </component>
 </project>
\ No newline at end of file
diff --git a/app/src/main/java/lu/circl/mispbump/auxiliary/KeyValue.java b/app/src/main/java/lu/circl/mispbump/auxiliary/KeyValue.java
index fe9b2e9..b0e02e1 100644
--- a/app/src/main/java/lu/circl/mispbump/auxiliary/KeyValue.java
+++ b/app/src/main/java/lu/circl/mispbump/auxiliary/KeyValue.java
@@ -4,6 +4,11 @@ public class KeyValue<K, V> {
     public K key;
     public V value;
 
+    /**
+     * Generates a generic key value pair.
+     * @param key key
+     * @param value value
+     */
     public KeyValue(K key, V value) {
         this.key = key;
         this.value = value;
diff --git a/app/src/main/java/lu/circl/mispbump/auxiliary/PreferenceManager.java b/app/src/main/java/lu/circl/mispbump/auxiliary/PreferenceManager.java
index 1906186..1963166 100644
--- a/app/src/main/java/lu/circl/mispbump/auxiliary/PreferenceManager.java
+++ b/app/src/main/java/lu/circl/mispbump/auxiliary/PreferenceManager.java
@@ -5,10 +5,14 @@ import android.content.SharedPreferences;
 
 import com.google.gson.Gson;
 
+import java.io.IOException;
 import java.security.InvalidAlgorithmParameterException;
 import java.security.InvalidKeyException;
 import java.security.Key;
+import java.security.KeyStore;
+import java.security.KeyStoreException;
 import java.security.NoSuchAlgorithmException;
+import java.security.cert.CertificateException;
 
 import javax.crypto.BadPaddingException;
 import javax.crypto.IllegalBlockSizeException;
@@ -39,11 +43,12 @@ public class PreferenceManager {
 
     /**
      * Helper class to save and retrieve (sensitive) information to and from SharedPreferences.
+     *
      * @param context for accessing the SharedPreferences file.
      * @return singleton instance
      */
     public static PreferenceManager getInstance(Context context) {
-        if(instance == null) {
+        if (instance == null) {
             instance = new PreferenceManager(context);
         }
 
@@ -53,6 +58,7 @@ public class PreferenceManager {
 
     /**
      * Saves user infos from "users/view/me" (encrypted)
+     *
      * @param user
      */
     public void setUserInfo(User user) {
@@ -77,6 +83,7 @@ public class PreferenceManager {
     }
 
     /**
+     * Returns the user information if already stored and decrypts it.
      *
      * @return decrypted user info if any, else null
      */
@@ -110,6 +117,7 @@ public class PreferenceManager {
 
     /**
      * Save user org infos from "organisations/view/{orgId}" (encrypted)
+     *
      * @param organisation Object representation of json organisation information
      */
     public void setUserOrgInfo(Organisation organisation) {
@@ -135,12 +143,13 @@ public class PreferenceManager {
     }
 
     /**
+     * Returns the user organisation information if already stored and decrypts it.
      *
      * @return decrypted user org info if any, else null
      */
     public Organisation getUserOrganisation() {
 
-        if(!preferences.contains(USER_ORG_INFOS)) {
+        if (!preferences.contains(USER_ORG_INFOS)) {
             return null;
         }
 
@@ -167,7 +176,8 @@ public class PreferenceManager {
 
 
     /**
-     * Saves the encrypted auth key/automation key
+     * Encrypts the automation key and stores it in preferences.
+     *
      * @param automationKey
      */
     public void setAutomationKey(String automationKey) {
@@ -189,6 +199,11 @@ public class PreferenceManager {
         }
     }
 
+    /**
+     * Decrypts the stored automation key and returns it.
+     *
+     * @return the decr
+     */
     public String getAutomationKey() {
 
         if (!preferences.contains(AUTOMATION_KEY)) {
@@ -215,6 +230,9 @@ public class PreferenceManager {
         return "";
     }
 
+    /**
+     * Delete the key to decrypt this entry and the entry itself.
+     */
     public void clearAutomationKey() {
         // remove the key from KeyStore
         KeyStoreWrapper keyStoreWrapper = new KeyStoreWrapper(KeyStoreWrapper.AUTOMATION_ALIAS);
@@ -227,8 +245,9 @@ public class PreferenceManager {
 
 
     /**
-     * Saves the encrypted URL of Misp Server
-     * @param serverUrl
+     * Encrypts the server url and stores it in preferences.
+     *
+     * @param serverUrl url of the corresponding misp instance
      */
     public void setServerUrl(String serverUrl) {
         try {
@@ -251,6 +270,11 @@ public class PreferenceManager {
         }
     }
 
+    /**
+     * Decrypts the stored server url and returns it
+     *
+     * @return decrypted misp instance url
+     */
     public String getServerUrl() {
 
         if (!preferences.contains(SERVER_URL)) {
@@ -278,6 +302,9 @@ public class PreferenceManager {
         return "";
     }
 
+    /**
+     * Delete the key to decrypt this entry and the entry itself.
+     */
     public void clearServerUrl() {
         // remove the key from KeyStore
         KeyStoreWrapper keyStoreWrapper = new KeyStoreWrapper(KeyStoreWrapper.SERVER_URL_ALIAS);
@@ -291,7 +318,10 @@ public class PreferenceManager {
 
     /**
      * Set if credentials (authkey & server url) should be saved locally.
+     *
      * @param save enable or disable
+     * @deprecated currently not used because automation key is needed to do requests to your misp instance.
+     * If this should be an option in future: misp automation key would be needed on each sync process.
      */
     public void setSaveCredentials(boolean save) {
         SharedPreferences.Editor editor = preferences.edit();
@@ -309,4 +339,4 @@ public class PreferenceManager {
         editor.clear();
         editor.apply();
     }
-}
+}
\ No newline at end of file
diff --git a/app/src/main/java/lu/circl/mispbump/restful_client/MispRestClient.java b/app/src/main/java/lu/circl/mispbump/restful_client/MispRestClient.java
index da61799..92ec224 100644
--- a/app/src/main/java/lu/circl/mispbump/restful_client/MispRestClient.java
+++ b/app/src/main/java/lu/circl/mispbump/restful_client/MispRestClient.java
@@ -25,6 +25,10 @@ import retrofit2.Response;
 import retrofit2.Retrofit;
 import retrofit2.converter.gson.GsonConverterFactory;
 
+/**
+ * Implementation of the RetroFit2 Misp client.
+ * In order to conveniently use this api some wrapper interfaces are implemented to return the requested API endpoint as java object.
+ */
 public class MispRestClient {
 
     // callbacks and interfaces
@@ -81,7 +85,7 @@ public class MispRestClient {
     }
 
     /**
-     * For development only!
+     * NOTE: for development only!
      * Accepts all certificates so self signed certs are also accepted.
      * @return OkHttpClient which accepts all certificates
      */
@@ -343,4 +347,4 @@ public class MispRestClient {
             }
         });
     }
-}
+}
\ No newline at end of file
diff --git a/app/src/main/java/lu/circl/mispbump/restful_client/MispRestService.java b/app/src/main/java/lu/circl/mispbump/restful_client/MispRestService.java
index 5ae9f93..eeb7786 100644
--- a/app/src/main/java/lu/circl/mispbump/restful_client/MispRestService.java
+++ b/app/src/main/java/lu/circl/mispbump/restful_client/MispRestService.java
@@ -8,6 +8,9 @@ import retrofit2.http.GET;
 import retrofit2.http.POST;
 import retrofit2.http.Path;
 
+/**
+ * RetroFit2 interface for communication with misp instances
+ */
 public interface MispRestService {
 
     // user routes
@@ -36,4 +39,4 @@ public interface MispRestService {
 
     @POST("servers/add")
     Call<MispServer> addServer(@Body MispServer server);
-}
+}
\ No newline at end of file
diff --git a/app/src/main/java/lu/circl/mispbump/security/AESSecurity.java b/app/src/main/java/lu/circl/mispbump/security/AESSecurity.java
index 427f87d..052b599 100644
--- a/app/src/main/java/lu/circl/mispbump/security/AESSecurity.java
+++ b/app/src/main/java/lu/circl/mispbump/security/AESSecurity.java
@@ -18,6 +18,7 @@ public class AESSecurity {
     private static final String KEY_PAIR_ALGORITHM = "EC";
     private static final int KEY_SIZE = 521; // 224 | 256 | 384 | 521
     private static final String KEY_AGREEMENT_ALGORITHM = "ECDH";
+    private static final String KEY_FACTORY_ALGORITHM = "EC";
 
     private static AESSecurity instance;
 
@@ -31,9 +32,9 @@ public class AESSecurity {
         initialize();
     }
 
-    /***
-     * Generates a public and a private key using an elliptic curve algorithm (256 bit)
-     * The private key is fed into the key agreement instance
+    /**
+     * Generates a public and a private key using an elliptic curve algorithm.
+     * The private key is fed into the key agreement instance.
      */
     private void initialize() {
 
@@ -52,9 +53,9 @@ public class AESSecurity {
         }
     }
 
-    /***
-     * Generates a shared secret with a given public key
-     * @param publickey
+    /**
+     * Generates a shared secret and derives an initialisation vector from it.
+     * @param publickey public key of the sync partner
      */
     public void setForeignPublicKey(PublicKey publickey) {
 
@@ -72,6 +73,11 @@ public class AESSecurity {
         }
     }
 
+    /**
+     *
+     * @param data
+     * @return
+     */
     public String encrypt(String data) {
         try {
 
@@ -93,6 +99,11 @@ public class AESSecurity {
         return data;
     }
 
+    /**
+     *
+     * @param data
+     * @return
+     */
     public String decrypt(String data) {
         try {
             Key key = generateKey();
@@ -119,9 +130,7 @@ public class AESSecurity {
     }
 
     private Key generateKey() {
-
         return new SecretKeySpec(sharedSecret, ENCRYPT_ALGORITHM);
-
     }
 
     public static String publicKeyToString(PublicKey key) {
@@ -129,11 +138,10 @@ public class AESSecurity {
     }
 
     public static PublicKey publicKeyFromString(String key) {
-
         try {
 
             byte[] input = Base64.decode(key, Base64.DEFAULT);
-            return KeyFactory.getInstance("EC").generatePublic(new X509EncodedKeySpec(input));
+            return KeyFactory.getInstance(KEY_FACTORY_ALGORITHM).generatePublic(new X509EncodedKeySpec(input));
 
         } catch (NoSuchAlgorithmException | InvalidKeySpecException e) {
             e.printStackTrace();
@@ -143,12 +151,9 @@ public class AESSecurity {
     }
 
     public static AESSecurity getInstance() {
-
         if(instance == null) {
             instance = new AESSecurity();
         }
-
         return instance;
     }
 }
-
diff --git a/app/src/main/java/lu/circl/mispbump/security/KeyStoreWrapper.java b/app/src/main/java/lu/circl/mispbump/security/KeyStoreWrapper.java
index 1396fae..2af8db5 100644
--- a/app/src/main/java/lu/circl/mispbump/security/KeyStoreWrapper.java
+++ b/app/src/main/java/lu/circl/mispbump/security/KeyStoreWrapper.java
@@ -40,10 +40,17 @@ public class KeyStoreWrapper {
 
     private String KEYSTORE_ALIAS;
 
+    /**
+     * Wraps the android key store to easily encrypt and decrypt sensitive data.
+     * @param alias identifies a key store entry (see public static ALIAS variables).
+     */
     public KeyStoreWrapper(String alias) {
         KEYSTORE_ALIAS = alias;
     }
 
+    /**
+     * @return wheter an entry for this alias already exists.
+     */
     private boolean isInitialized() {
         try {
             KeyStore ks = KeyStore.getInstance(KEYSTORE_PROVIDER);
@@ -66,6 +73,10 @@ public class KeyStoreWrapper {
     }
 
 
+    /**
+     *
+     * @return SecretKey associated with the given alias.
+     */
     private SecretKey getStoredKey() {
         try {
 
@@ -88,6 +99,10 @@ public class KeyStoreWrapper {
         return null;
     }
 
+    /**
+     * Generates a new key.
+     * @return the newly generated key.
+     */
     private SecretKey generateKey() {
         try {
 
@@ -117,7 +132,9 @@ public class KeyStoreWrapper {
         return null;
     }
 
-
+    /**
+     * Deletes the key associated with the current alias.
+     */
     public void deleteStoredKey() {
         try {
             KeyStore ks = KeyStore.getInstance(KEYSTORE_PROVIDER);
@@ -134,6 +151,16 @@ public class KeyStoreWrapper {
         }
     }
 
+    /**
+     * Encrypt data with given algorithm and key associated with alias.
+     * @param data data to encrypt.
+     * @return encrypted data as String.
+     * @throws NoSuchPaddingException
+     * @throws NoSuchAlgorithmException
+     * @throws InvalidKeyException
+     * @throws BadPaddingException
+     * @throws IllegalBlockSizeException
+     */
     public String encrypt(String data) throws NoSuchPaddingException, NoSuchAlgorithmException, InvalidKeyException, BadPaddingException, IllegalBlockSizeException {
         SecretKey secretKey;
 
@@ -153,6 +180,17 @@ public class KeyStoreWrapper {
         return ivString + ":::" + encryptedDataString;
     }
 
+    /**
+     * Decrypts data with given algorithm and key associated with alias.
+     * @param input encrypted data.
+     * @return decrypted data as String.
+     * @throws NoSuchPaddingException
+     * @throws NoSuchAlgorithmException
+     * @throws InvalidAlgorithmParameterException
+     * @throws InvalidKeyException
+     * @throws BadPaddingException
+     * @throws IllegalBlockSizeException
+     */
     public String decrypt(String input) throws NoSuchPaddingException, NoSuchAlgorithmException, InvalidAlgorithmParameterException, InvalidKeyException, BadPaddingException, IllegalBlockSizeException {
 
         // extract iv from save data
@@ -169,7 +207,10 @@ public class KeyStoreWrapper {
         return new String(cipher.doFinal(data), StandardCharsets.UTF_8);
     }
 
-
+    /**
+     * Removes all aliases and the associated keys.
+     * Note: all encrypted data cannot be decrypted anymore!
+     */
     public static void deleteAllStoredKeys() {
         try {
 
@@ -195,4 +236,4 @@ public class KeyStoreWrapper {
             e.printStackTrace();
         }
     }
-}
+}
\ No newline at end of file