Adam L. Young: Building Robust Backdoors In Secret Symmetric Ciphers

Black Hat Briefings, Las Vegas 2005 [Audio] Presentations from the security conference

This talk will present recent advances in the design of robust cryptographic backdoors in secret symmetric ciphers (i.e., classified or proprietary ciphers). The problem directly affects end-users since corporations and governments have in the past produced secret symmetric ciphers for general use (e.g., RC4 and Skipjack, respectively). The problem itself is challenging since it involves leaking secret key material in the ciphertexts that are produced by a deterministic function, whereas traditional subliminal channels have relied on the use of randomized cryptographic algorithms. Such attacks can be regarded as advanced Trojan horse attacks since the secret block cipher securely and subliminally transmits the symmetric key of the sender and receiver to the malicious designer and confidentiality holds even when the cipher is made public. The material that will be surveyed was published in Fast Software Encryption (FSE '98), the Australasian Conference on Information Security and Privacy (ACISP '03), and Selected Areas in Cryptography (SAC '04). Adam Young received his BS degree in Electrical Engineering from Yale University in '94, his MS degree in Computer Science from Columbia University in '96. He was awarded his PhD degree in Computer Science with distinction from Columbia University in '02. He has authored publications in IEEE Foundations of Computer Science, Crypto, Eurocrypt, Asiacrypt, Security in Communication Networks (SCN), Fast Software Encryption, Algorithmic Number Theory Symposium (ANTS), PKC, CT-RSA, SAC, IEEE Security and Privacy, Cryptographic Hardware and Embedded Systems (CHES), ACISP, and the IEEE Information Assurance Workshop. He is the author of the book "Malicious Cryptography: Exposing Cryptovirology" that is co-authored with Dr. Moti Yung. Adam has given invited talks at Xerox PARC, MITRE, Bell Labs, NYU, Sandia National Labs, the Naval Postgraduate School, the AMS-MMS special session on coding theory and cryptography, and the 2nd International Conference on Advanced Technologies for Homeland Security (ICATHS '04). In April Adam will be giving a talk at the DIMACS Workshop on Theft in E-Commerce that is being held at Rutgers University. Adam's work experience includes serving as a cryptographic consultant for CertCo, Inc., performing research for Lucent as a Member of Technical Staff, acting as a Principal Engineer for Lockheed Martin Global Telecommunications, and conducting Federally funded research for the DoD.