The present invention discloses a centralized 
certificate management system for 
thin client devices in data networks and has particular applications to systems having a large number of the thin clients serviced by a 
proxy server through which the thin clients communicate with a plurality of secure 
server computers over a data network. According to one aspect, the present invention comprises a 
certificate management module that causes the 
server device to manage digital certificates for each of the 
thin client devices. To minimize the latency of obtaining certificates for each of the 
thin client devices, the 
certificate management module reserves a fixed number of free certificates signed by a 
certificate authority and their respective private keys in a certificate 
database and frequently updates the free certificate according to a certificate updating message. Whenever a user account is created for a thin 
client device, the certificate management module fetches one or more free certificates from the certificate 
database and associate the fetched certificates to the created account and meanwhile the certificate management module creates new free certificates with the 
certificate authority to fill in the certificate 
database. Apart from the tradition of obtaining certificates locally in 
client devices that normally have sufficient computing power, the present invention uses the computing resources in a 
server device to carry out the task of obtaining and maintaining certificates asynchronously in the 
proxy server and further. These and other features in the present invention dramatically minimize the demands for computing power and memory in thin 
client devices like mobile devices, cellular phones, landline telephones or 
Internet appliance controllers.