Chen Chen 0013 Himanshu Raj Stefan Saroiu Alec Wolman cTPM: A Cloud TPM for Cross-Device Trusted Applications. 187-201 2014 NSDI https://www.usenix.org/conference/nsdi14/technical-sessions/presentation/chen conf/nsdi/2014 db/conf/nsdi/nsdi2014.html#ChenRSW14