This digital era uses lots of images in communication, which are confidential and large in volume. The transmission channel thus arises the question of security as well as transmission load. To date, several works are there to solve this issue. However, they fail to provide a single unit that gives these two facilities in a unified way. This paper presents a novel technique of unification of image compression and encryption in a single module via sparse-representation of image frames and hyper-chaotic encryption techniques. In this work, we have proposed a method to estimates the sparse vectors of a given image using a regularized trained over-complete dictionary and encrypt the non-zero coefficients of the sparse vectors using key-streams generated by a hyper-chaotic system. This sparse coding based encryption technique provides a higher compression ratio (CR) compared to some recently proposed techniques on one side and increases security level on the other side. Moreover, the security is strengthened by using this key-sequence in different steps in the encryption scheme. Thus the compressed-encrypted outputs are stronger than simple chaotic encryption against any intruder. The efficiency and authenticity of the proposed algorithm are verified through several quality-index e.g. entropy, CR, etc. The resistivity of the proposed algorithm toward the known or chosen-plaintext attack is also analyzed. The results of the key sensitivity test, and cropping attack test also ensure the authors’ claim. The comparison of the proposed technique with some recently published works justifies the reliability of this work.

这个数字时代在通信中使用了大量图像，这些图像是机密的，而且数量巨大。因此，传输通道出现了安全性以及传输负载的问题。迄今为止，已经有一些作品可以解决这个问题。但是，他们无法提供一个统一的单元来提供这两个功能。本文提出了一种通过图像帧的稀疏表示和超混沌加密技术在单个模块中统一图像压缩和加密的新技术。在这项工作中，我们提出了一种使用正则化训练过的完全字典来估计给定图像的稀疏向量，并使用超混沌系统生成的密钥流对稀疏向量的非零系数进行加密的方法。与某些最近提出的技术相比，这种基于稀疏编码的加密技术在一侧提供了更高的压缩率（CR），而在另一侧则提高了安全级别。此外，通过在加密方案的不同步骤中使用此密钥序列可以增强安全性。因此，针对任何入侵者，压缩加密输出都比简单的混沌加密更强大。通过几种质量指标，例如熵，CR等，验证了所提出算法的效率和真实性。还分析了所提出算法对已知或选择明文攻击的抵抗力。密钥敏感性测试和裁剪攻击测试的结果也确保了作者的主张。所提出的技术与最近发表的一些作品的比较证明了这项工作的可靠性。