安全通道協定是保護爪哇卡的資料傳輸的門戶，用戶端和卡片必須取得相互間的認證，才能做進一步的溝通， 現行大多使用的版本是SCP02(Secure Channel Protocol 02)版， 安全機制是用DES(Data Encryption Standard)加解密，安全強度上稍嫌薄弱，在安全需求日益增加的情形下，會逐漸替換為使用AES(Advanced Encryption Standard)[3]密碼演算， 其機制定義在SCP03(Secure ChannelProtocol 03)[2]規範中，文中會提及SCP03內容，以及開發過程所做的努力，為爪哇卡未來能夠再進一步加強安全等級做準備。

Secure channel protocol provides a means by which a card may communicate with an off-card entity within a logically secure environment. The current version is Secure Channel Protocol 02 and the security mechanism lies on DES encrypt/decryption to protect the communication. It’s strength became less enough in recent security requirement. The mechanism turn into using AES architecture as defined in SCP03. We will mention the content of SCP03 and the effort we did in development in the following sections. Hope this will be a good preparation to enhance the security of Java card in the future.