# A Chaotic Compressive Sensing Based Data Transmission Method for Sensors within BBNs
## 2 Related Work
A key generation method that introduced attributes of wireless channels of BBNs was raised in [28]. [PERSON] et al. purveyed an anonymous authentication method for BBNs, which could resist man-in-the-middle attacks [29]. Finally, in [30], [PERSON] et al. applied homomorphic encryption to BBNs to realize data collection and query without the neglect of privacy protection. The following paragraphs contain a brief introduction of the main research progress in (compressive sensing) CS. CS theory is a signal sampling and compression theory that was first proposed by [PERSON] in 2006 [31; 32; 33]. Once put forward, this theory has been widely used in telecommunications, networks, signal processing, radars, aviation, biomedical applications, etc. CS does not merely address the problem of data compression. It also achieves data encryption simultaneously. Such characteristics may meet the requirements of data compression and encryption of sensor networks. Noticeably, CS can realize data compression and encryption in solely one step [34; 35; 36]. [PERSON] et al. improved the generation process of the measurement matrix and enhanced the security level of data transmission by introducing chaotic systems, but concealing critical information was not considered [37]. [PERSON] et al. combined CS and data hiding, although their scheme has not achieved the acme of perfection in terms of resisting statistical attacks [38]. To the best of our knowledge, research on BBNs commonly considers data security, energy efficiency, and critical information concealment issues separately. Although a proportion of existing CS based schemes could accomplish data encryption and compression at the same time, or could realize efficient data transmission to a certain extent, they did not address the problems that concerns critical information concealment. According to the characteristics of BBNs and the above-mentioned issues to be settled, this paper proposes a secure and efficient data transmission method based on the chaotic CS model and there are three main contributions. (1) For the purpose of achieving energy efficiency, it should be considered that the capacity of batteries installed on BBN sensors is fairly limited, and recharging or replacing these batteries are often not convenient, especially when the batteries have been implanted into human bodies. And because of the expansion of network scales, the complexity of natural or external environments, or the huge volume of data to be transmitted, power of BBN batteries may consume fast. So, energy saving issues become a must while designing data transmission schemes applied in BBNs. Based on CS theory, this paper gives an efficient data transmission method, which completes data compression, encryption and critical information concealment simultaneously. (2) For the purpose of realizing transmission security, it should be considered that the majority of data transmitted in BBNs may contain confidential sections, especially when the data concern vital signs of human beings or personal information. Especially, while being applied to medical care or military affairs, BBNs highly probably transmit a substantial amount of data involving critical or private information. On the one hand, under complex circumstances of the real world, open links may be vulnerable to be eavesdropped, which may lead to critical information leaking or other problems. Moreover, even if data are transmitted solely in internal channels, secure data transmission scheme is also imperative, since data may be forwarded several times and these processes may generate many copies of original signals involving critical information. Based on chaos theory, this paper designs a novel secure data transmission method, which could enhance the security level of data transmission by breaking the statistical patterns of original data, providing large key space and sensitivity of the initial values, etc. (3) For the purpose of enhancing flexibility, the proposed method considers from two aspects.