  Machine learning techniques have had a long list of applications in recent
years. However, the use of machine learning in information and network security
is not new. Machine learning and cryptography have many things in common. The
most apparent is the processing of large amounts of data and large search
spaces. In its varying techniques, machine learning has been an interesting
field of study with massive potential for application. In the past three
decades, machine learning techniques, whether supervised or unsupervised, have
been applied in cryptographic algorithms, cryptanalysis, steganography, among
other data-security-related applications. This paper presents an updated survey
of applications of machine learning techniques in cryptography and
cryptanalysis. The paper summarizes the research done in these areas and
provides suggestions for future directions in research.
