In this paper, a systematic method for developing a binary version of a given transform by
using the Walsh-Hadamard transform (WHT) is proposed. The resulting transform …

Speech scrambling techniques are used to scramble clear speech into unintelligible signal
in order to avoid eavesdropping. Analog scramblers are intended in applications where the …

The security problem of speech communication has always been a demanding problem in
military and business areas. A common approach to realizing end-to-end security is the use …

Image-scrambling schemes are designed to render the image content unintelligible. Wyner
has proposed an elegant one-dimensional (1-D) scrambling scheme without bandwidth …

This paper proposes a new and efficient chaos-based cryptosystem for multiuser speech
encryption. In this regards, Chua chaotic systems are added to the transmitters and receiver …

(57) ABSTRACT A secure communication apparatus may include a security module for
generating an encrypted bitstream by encrypting at least a portion of data forming a …

Speech privacy techniques are used to scramble clear speech into an unintelligible signal in
order to avoid eavesdropping. Some analog speech-privacy equipments (scramblers) have …

Conventional speech scramblers have three disadvantages, including heavy
communication overhead, signal features underexploitation, and low attack resistance. In …

Audio scrambling can be employed to ensure confidentiality in audio distribution. We first
describe scrambling for raw audio using the discrete wavelet transform (DWT) first and then …

(FPGA) based secured speech communication system. Data-size is one of the major
concerns of cryptographic systems. To maintain same data-rate compression is performed at …