Georgia Tech Information Processing, Communications and Security (IPCAS) Research Lab Research Lab

Cryptography and Network/Communications Security Developments in the computer and communication technology have brought a new dimension to the Information Age. Real-time exchange of information regardless of location and distance has greatly increased both the pace of business and the number of ways in which we communicate. The widespread availability and transmission of such information demands new approaches in cryptography. The objective is to build secure and reliable networks out of less secure and less reliable resource constrained devices. Our work spans the range from theoretical cryptography to applications; including significant research efforts in development of new cryptographic primitives, cryptanalysis, and applications from wireless and ad-hoc (sensor) networks to delay-tolerant (DTN) and space-time networks.

 

Public Key Cryptography | Wavelet Cryptography Random Key Pre-distribution | Authentication/Availability Trust and Reputation Systems | Recommendation Systems

 

Wavelet Block/Stream Cipher

The growth of the computing technology has stimulated phenomenal development in pervasive computing. However, pervasive computing has pervasive problems. The widespread availability and transmission of information makes security and privacy as one of the most crucial issues of today's networks. Strong encryption systems are crucial in stopping hackers from listening to cellular voice and stealing credit card numbers, medical records, and other sensitive information from networks. Our team effort is aimed at developing new symmetric key primitives that are particularly suitable for handheld and resource constrained devices (PDA's, two-way paging, sensors, etc.). In the design of security for resource limited devices, we must consider their low power, strict processing requirements and storage limitations. We present a new private key cryptosystem based on the finite-field wavelet. The encryption and decryption are performed by the synthesis and analysis banks of the nonlinear finite-field wavelet transform, whose filter coefficients are determined by the keys of the users. The proposed cryptographic system can operate in either stream-cipher or block-cipher modes depending on whether the filter banks perform linear or circular convolution. The proposed block cipher system has a key length of 16 symbols (128 bits) and an input block size of 30 symbols (240 bits) from GF(256). Our results suggest that the wavelet block cipher has comparable computational complexity to AES and approximately half the complexity of DES. The security is tied to the length of the wavelet basis function and to the nonlinearity within the wavelet transform. We study the security of the wavelet cryptosystem in response to classical attacks and those specific to this algorithm, particularly those which use variations of divide and conquer, interpolation attack, and discrete Fourier transform techniques.