Joint block and stream cipher based on a modified skew tent map
Date
2019-08-29
Authors
Qumsieh, Rawan
Farajallah, Mousa
Hamamreh, Rushdi
Journal Title
Journal ISSN
Volume Title
Publisher
Springer
Abstract
Image encryption is very different from that of texts due to the bulk data capacity and the
high redundancy of images. Thus, traditional methods are difficult to use for image encryption
as their pseudo-random sequences have small space. Chaotic cryptography use chaos
theory in specific systems working such as computing algorithms to accomplish dissimilar
cryptographic tasks in a cryptosystem with a fast throughput. For higher security, encryption
is the approach to guard information and prevent its leakage. In this paper, a hybrid encryption
scheme that combines both stream and block ciphering algorithms is proposed in order
to achieve the required level of security with the minimum encryption time. This scheme is
based on an improved mathematical model to cover the defects in the previous discredited
model proposed by Masuda. The proposed chaos-based cryptosystem uses the improved
Skew Tent Map (STM) RQ-FSTM as a substitution layer. This map is based on a lookup
table to overcome various problems, such as the fixed point, the key space restrictions, and
the limitation of mapping between plain text and cipher text. It uses the same map as a generator
to change the byte position to achieve the required confusion and diffusion effects.
This modification improves the security level of the original STM. The robustness of the
proposed cryptosystem is proven by the performance and the security analysis, as well as
the high encryption speed. Depending on the results of the security analysis the proposed
system has a better dynamic key space than previous ones using STM, a double encryption
quality and a better security analysis than others in the literature with speed convenience to
real-time applications.
Description
Keywords
Stream cipher , Block cipher , Finite State Tent Map , Cryptosystem
Citation
Qumsieh, R., Farajallah, M. & Hamamreh, R. Multimed Tools Appl (2019). https://doi.org/10.1007/s11042-019-08112-z