You are presented with multiple paper abstracts, alongside the associated literature review and chapter titles. Given the provided information, you are going to do a literature review. Please generate a coherent literature review that synthesizes the content, draws connections between different works, highlights major findings, and identifies any gaps in the existing research.

Literature Review Title: A Survey of Security and Privacy Issues for Biometrics Based Remote Authentication in Cloud 
Chapter Title:  Introduction 
1. Abstract of Cited Paper (BIB001):  With their increasing popularity in cryptosystems, biometrics have attracted more and more attention from the information security community. However, how to handle the relevant privacy concerns remains to be troublesome. In this paper, we propose a novel security model to formalize the privacy concerns in biometric-based remote authentication schemes. Our security model covers a number of practical privacy concerns such as identity privacy and transaction anonymity, which have not been formally considered in the literature. In addition, we propose a general biometric-based remote authentication scheme and prove its security in our security model.

Literature Review:
Amount of digital content has been growing day by day with the exponential increase in number of devices connected to Internet. High volume data not only demand for huge storage space, but also looking for intelligent processing in a cost-effective manner. The popular choice in such cases is the cloud environment, which provides unlimited storage space, on demand service, parallel processing and rapid distribution of data. Cloud service provider provides a flexible way for users to access their data from anywhere and at any time. The flexibility of data usage however takes away control from the data owner. Thus the manner in which data are accessed, and by whom, is essentially under the control of cloud service provider. In such a scenario, the authentication of user is very important, so as to guarantee security of data and privacy of data source. Remote user authentication mechanism is useful in distributed domain to identify validity of remote users. There exist several techniques for remote authentication. Some of the essential requirements for enhancing quality of remote authentication in cloud are given below. • Third party cloud service provider is not able to retrieve original data, or associated metadata stored in cloud. • Ensure that an impostor cannot be impersonated as a legitimate user. • System should be capable to respond to any incoming valid request. • No intruder is allowed to modify original message. • If timestamps are used, then it must be synchronized. • System must optimize bandwidth usage in a cost effective manner. Password-based authentication with smart card can be used to identify the validity of a remote user. Traditional identity-based authentication mechanisms are mainly based on password, which are very easy to break because of its simplicity. Cryptographic secret keys can also be used in remote authentication framework. Major drawback is that they are difficult to memorize, lost or even be stolen. As a result, it is very difficult to identify valid users accurately. As opposed to traditional password based remote user authentication, biometrics based authentication is increasingly popular because of its reliability BIB002 and efficiency to authenticate remote users. Cloud based remote authentication provides enhanced security by using biometrics traits BIB001 such as fingerprint verification, keystroke analysis, ECG analysis, iris analysis, facial analysis, handwritten signature verification etc. Each biometrics trait used in authentication has its own strengths and weaknesses. Biometrics based authentication may be unimodal having single biometrics trait or multimodal, combining multiple biometrics features. Cloud based biometrics technology has high potential market value and attracts interest of many researchers from all around the world. Cloud framework and remote authentication technique have several challenges of their own. Preserving a balance between security and privacy is a major concern in remote framework of cloud. Privacy is the ability to decide what information should go where. Security acts as significant safeguard for privacy by protecting data. Security and privacy are often considered from two complementary angles. Despite a couple of surveys of biometrics authentication or remote authentication, a comprehensive survey of biometrics based remote authentication in cloud does not exist. The main objective of this paper is to study the balance between security and privacy in biometrics based remote authentication and point out the research gap in this domain. The contributions of this paper are as follows. ─ To extensively survey some of the existing schemes that may be used for biometrics based remote authentication in cloud and determine general trends. ─ To discuss open issues for future research area. The rest of the paper contains the following. Section 2 gives a brief introduction of security challenges faced by biometrics techniques. Section 3 presents an extensive survey of some of the existing schemes in this area. Section 4 gives a comparative analysis of this study. Section 5 presents the open research issues in this area, and section 6 concludes the paper.