Design and implementation of a server-aided PKI service (SaPKI)

More and more mobile applications require the ability to issue digital signatures. Traditionally, digital signatures are based on asymmetric cryptographic techniques which make them computationally expensive. Currently, all mobile devices tend to have limited computational capabilities and equally limited power. This makes them ill-suited for complex cryptographic computations. We designed a server-aided PKI service (SaPKI) to offload work from clients in mobile networks such as GSM and CDMA. Mobile clients can utilized the powerful (both CPU speed and power supply) SaPKI server to generate RSA keys and digital signatures. The paper details the implementation of SaPKI service. A secure "cell phone-banking" application has been implemented on SaPKI architecture in CDMA-IX mobile network. After thorough performance analysis, we concluded that SaPKI could significantly improve the performance of mobile client\´s cryptographic operation.