Mobile Phone Based Portable Key Management

Laptops are easy to lose to leak sensitive data, storing data in encrypted file systems does not sufficiently solve this problem. To decrypt a file, such systems often need to require a user to manually provide keys each time, which is annoying and directly discourages users to protect sensitive data effectively. The paper first presents a Portable key (PK) scheme, which employs a mobile phone to manage keys/passwords of a laptop. The laptop automatically requests key material from the mobile phone through Bluetooth link if needed, which sets users free from manually providing keys/passwords frequently. A remote control protocol is also provided to guarantee the security in case the mobile phone is lost. Finally, the paper extends the BAN logic and gives the formal security analysis and implementation, formal analysis shows that the scheme is secure to some typical attacks; implementation shows that the scheme brings little additional load to both sides and the protocol is efficient and practical.