# The Dichotomy of Neural Networks and Cryptography: War and Peace
## 2 Existing Surveys and Motivations  
Although there might be some related surveys, their shortcomings motivate the work of this paper. These shortcomings can be itemized as follows. * There are a few reviews on the role of artificial intelligence (AI), and especially NNs in cryptography. However, to the best of our knowledge, there is no comprehensive survey on the roles of cryptography in secure neural networks. Moreover, there is no survey on the role of neural networks in aggressive activities against cryptography. * Some existing surveys are too outdated for such a dynamic research area [28; 29; 30]. * Most of them fail to develop directions for future research in this area [31; 32]. The above shortcomings highlight the importance of our work in this paper with the contributions mentioned in Section 1. In the following, some relevant surveys are briefly discussed ordered by their publication year. There have been several past surveys studying the relationship of AI and cryptography. Figure 1 shows the general relationship between the two technologies, in places they are adversaries and others they combine to create a benevolent system. Some older surveys study technology which is no longer relevant to the current discussion. Many of the newer surveys take too narrow field to garner insight into the future of the field. [PERSON] et al. looked at the current state of cryptography by defining the goals of security systems and discussing possible solutions [28]. Concerning NNs this study mentions the application of cellular NNs (CeNNs) too implement Boolean mappings and the application of cellular automata (CeA) to encrypt data. Ten years later [PERSON] et al. summarized uses of NNs in private key systems, an image encryption scheme, pseudo random number generation, the analysis and generation of digital watermarks [29]. That same year [PERSON] and [PERSON] proposed using a specific NN model for 802.16 to share private keys over a public channel through training synchronization [30]. [PERSON] and [PERSON] provided another broad review of NN's ability to improve on current cryptographic techniques [31]. This paper fails to mention any techniques that the the 2008 review did not mention, but it gives an overview of some attacks on NN-improved cryptography systems. [PERSON] and [PERSON] compared key exchange schemes using NNs and quantum computers as means to improve on current key management systems in 2016 [32]. This paper concluded that NN Key exchange is more practical but has yet to be practically implemented and the theory needs hardening against unconventional attacks. [PERSON] et al. published a paper in 2019 referencing the work of [PERSON] and [PERSON] also comparing NNs and quantum computers ability to improve key exchange systems [33]. This paper also come to the conclusion that current quantum solutions cannot be broadly implemented and NNs could be used but it does not bring up any specific implementations or steps needed to further research. [PERSON] et al. studied current image encryption techniques using NN to propose a possible architecture for encrypting medical images [34]. [PERSON] et al. [35] published a comprehensive survey documenting various NN cryptography techniques along with verified attacks and some published solutions for the attacks. Through this survey [PERSON] et al. found that cryptographic NN systems are trending in two directions, providing a low computation cost encryption solution and being a viable post-quantum encryption primitive. Table 1 provides a summary of existing surveys in order to make it easy to see their shortcomings and compare them with our survey. In Table 1, each entry in the first column contains one of the surveys studied in this section. The second column indicates the publication year of the related survey. Outdated surveys can be identified using this column. The next three columns indicate the aspects of the NN-crypto dichotomy (partially) covered by each survey.