This thesis describes two proposed schemes that could be used to secure mobile messaging (SMS/MMS) as well as one scheme that could be used to secure mobile content. The security services we considered in securing the mobile messages are confidentiality, authentication, non-repudiation and integrity. We used Identity Based Cryptography in order to secure the mobile messaging and Blowfish algorithm to secure the mobile content. Due to some of the disadvantages imposed by the Identity Based Cryptography, we recommended using it along with the RSA algorithm. The proposed schemes were implemented in java and tested on an actual device, Nokia N70. In addition, we measured the time required by each of the algorithms we used to encrypt/decrypt a certain number of bytes. We found that the time taken by RSA and Blowfish algorithms will not be noticeable by the user. However, since the implementation of the Identity Based Cryptography we used was not meant to run on mobile devices, we encountered a noticeable delay whenever encrypting/decrypting the data using this algorithm. Securing the SMS messages will make it to be considered as one of the proposed means that could be used to conduct m-commerce. In addition, securing the MMS messages and the mobile content will increase the usability and the reliability of the mobile phones especially to the users on the move.