The exponential growth of technologies and online applications in the last decade attracts researchers toward using Machine Learning (ML) to provide information security. In today's world, ML has proven itself by performing outstandingly on various issues and challenges of real-world applications. It has a vital domain of applications, one of which is cryptography. Cryptography is used to build a secure cryptosystem to provide information security. Although, the use of ML in cryptography is not novel. In the last decade, many notable machine-learning approaches have been applied in cryptography to achieve significant information security. This review paper looks at emerging research into applying ML approaches to cryptography. Moreover, we discuss the key concepts of ML and cryptography, summarize them, and list the future research directions.