Public Key Infrastructures suffer from usability and security problems associated with the request for and secure management of end user credentials. Online credential repositories provide mechanisms to ease these shortcomings but pose attractive targets for attacks due to the accumulation of credentials and the need for remote access to these credentials. Through the extension of an existing credential repository with a cryptographic co-processor for secure storage of credentials an increase in the security of the service can be achieved. This higher security permits the use of online credential repositories with a wide variety of certificates without violating certification authority regulations. Also, the improved performance afforded by hardware support improves the scalability of a centralized credential storage.