移動裝置一次性密碼（以下簡稱為MOTP）是為了提高使用澳門郵電電子證書服務的安全性及便利性而開發的應用程式。傳統上當用戶進行電子簽署時需同時提供智能卡及密碼作驗證，而當用戶申請使用MOTP後，用戶可輸入電子證書中的電郵地址、密碼及由本程式產生之動態密碼作為驗證（*需應用程式配合）。

“Mobile One time password” abbreviated as “MOTP”, it is developed for improving the security and convenience of using digital certificate issued by Macau Post and Telecommunications Bureau. Traditionally, users are required to provide smart card and password when digital signing. After applied MOTP service, users input email registered in e-certificate, password and passcode generated by this MTOP apps instead.(*Required application support).