The document discusses secure elements in mobile phones which provide security and confidentiality for mobile transactions. A secure element is isolated in the phone's operating system and hardware, and can only be accessed by authorized programs after entering a PIN. Current implementations of secure elements include being embedded in phones, located on SIM cards, or using removable secure element cards. The document proposes solutions for incorporating secure elements in phone memory, SIM cards, or external SD cards to enable encrypted transactions using protocols like NFC, SMS, and HTTPS.