Technical Reports (CIS)

Document Type

Technical Report

Date of this Version

January 2006


University of Pennsylvania Department of Computer and Information Science Technical Report No. MS-CIS-06-18.


We investigate the security properties of isotropic channels, broadcast media in which a receiver cannot reliably determine whether a message originated from any particular sender and a sender cannot reliably direct a message away from any particular receiver. We show that perfect isotropism implies perfect (information-theoretic) secrecy, and that asymptotically close to perfect secrecy can be achieved on any channel that provides some (bounded) uncertainty as to sender identity. We give isotropic security protocols under both passive and active adversary models, and discuss the practicality of realizing isotropic channels over various media.


unconditional security, secret-key agreement, provable security, isotropic channels



Date Posted: 08 February 2007