diff --git a/programs/light_client/Wallet.cpp b/programs/light_client/Wallet.cpp
index ffaa7673..dfdcb370 100644
--- a/programs/light_client/Wallet.cpp
+++ b/programs/light_client/Wallet.cpp
@@ -131,9 +131,16 @@ bool Wallet::isLocked()const
    if( !isOpen() ) return true;
    return false;
 }
-QString Wallet::unlock( QString password )
+bool Wallet::unlock( QString password )
 {
-   return QString();
+   if( !isLocked() ) return true;
+   auto pw_str                  = password.toStdString();
+   auto password_hash           = fc::sha512::hash( pw_str.c_str(), pw_str.size() );
+   auto plain_txt = fc::aes_decrypt( password_hash, _data.encrypted_master_key );
+   _decrypted_master_key = fc::raw::unpack<fc::sha512>(plain_txt);
+   if( _data.master_key_digest != fc::sha512::hash(_decrypted_master_key) )
+      _decrypted_master_key = fc::sha512();
+   return !isLocked();
 }
 
 bool Wallet::lock()
@@ -146,7 +153,15 @@ bool Wallet::lock()
 bool  Wallet::changePassword( QString new_password )
 {
    if( !isOpen() ) return false;
-   return false;
+   if( isLocked() ) return false;
+
+   auto pw_str                  = new_password.toStdString();
+   auto password_hash           = fc::sha512::hash( pw_str.c_str(), pw_str.size() );
+   _data.encrypted_master_key   = fc::aes_encrypt( password_hash, fc::raw::pack(_decrypted_master_key) );
+
+   save();
+
+   return true;
 }
 
 QString Wallet::getActivePrivateKey( QString owner_pub_key, uint32_t seq )
diff --git a/programs/light_client/Wallet.hpp b/programs/light_client/Wallet.hpp
index acc25838..35ae7011 100644
--- a/programs/light_client/Wallet.hpp
+++ b/programs/light_client/Wallet.hpp
@@ -68,10 +68,10 @@ class Wallet : public QObject
       /** @pre hasBrainKey() */
       Q_INVOKABLE QString getBrainKey();
 
-      Q_INVOKABLE bool    isLocked()const;
-      Q_INVOKABLE QString unlock( QString password );
-      Q_INVOKABLE bool    lock();
-      Q_INVOKABLE bool    changePassword( QString new_password );
+      Q_INVOKABLE bool isLocked()const;
+      Q_INVOKABLE bool unlock( QString password );
+      Q_INVOKABLE bool lock();
+      Q_INVOKABLE bool changePassword( QString new_password );
 
       /**
        * @pre !isLocked();