diff --git a/app/src/main/java/com/mylloon/mobidl/Credentials.kt b/app/src/main/java/com/mylloon/mobidl/Credentials.kt
index 9b1acb6..85b2506 100644
--- a/app/src/main/java/com/mylloon/mobidl/Credentials.kt
+++ b/app/src/main/java/com/mylloon/mobidl/Credentials.kt
@@ -10,12 +10,12 @@ import java.security.*
 
 class Credentials {
 
-    private val provider = "AndroidKeyStore"
-    private val aliasKeyStore = "MobiDL"
-    private val transformation = "RSA/ECB/PKCS1Padding"
+    private val provider = "AndroidKeyStore" // location of the key
+    private val aliasKeyStore = "MobiDL" // name of the key
+    private val transformation = "RSA/ECB/PKCS1Padding" // 'type' of the key
 
     @RequiresApi(Build.VERSION_CODES.M)
-    fun generateKey() {
+    fun generateKey() { // generate RSA Keys
         val keyPairGenerator = KeyPairGenerator.getInstance(
             KeyProperties.KEY_ALGORITHM_RSA, provider
         )
@@ -30,26 +30,26 @@ class Credentials {
         keyPairGenerator.generateKeyPair()
     }
 
-    private fun getPublicKey(): PublicKey {
+    private fun getPublicKey(): PublicKey { // Get the Public RSA key from the Android KeyStore
         val keyStore: KeyStore = KeyStore.getInstance(provider)
         keyStore.load(null)
         return keyStore.getCertificate(aliasKeyStore).publicKey
     }
 
-    private fun getPrivateKey(): PrivateKey {
+    private fun getPrivateKey(): PrivateKey { // Get the Private RSA key from the Android KeyStore
         val keyStore: KeyStore = KeyStore.getInstance(provider)
         keyStore.load(null)
         return keyStore.getKey(aliasKeyStore, null) as PrivateKey
     }
 
-    private fun encrypt(message: String): ByteArray {
+    private fun encrypt(message: String): ByteArray { // Encrypt a string with the public RSA key
         val cipher = Cipher.getInstance(transformation)
         cipher.init(Cipher.ENCRYPT_MODE, getPublicKey())
 
         return cipher.doFinal(message.toByteArray())
     }
 
-    private fun decrypt(message: ByteArray): String {
+    private fun decrypt(message: ByteArray): String { // Decrypt an encrypted string with the private RSA key
         val cipher = Cipher.getInstance(transformation)
         cipher.init(Cipher.DECRYPT_MODE, getPrivateKey())