25 Copyright © 2020, IGI Global. Copying or distributing in print or electronic forms without written permission of IGI Global is prohibited. Chapter 2 DOI: 10.4018/978-1-7998-1290-6.ch002 ABSTRACT This chapter presents the possibilities of applying cryptography and steganography in design advanced methods of medical software. The proposed solution has two modules: medical data encryption and medical data hiding. In the frst module for the encryption of patient data a Catalan crypto-key is used combined with the LatticePath combinatorial problem. In the second module for hiding patient data, the Catalan stego-key and medical image is used. The objective of the second part is to explain and investigate the existing author’s method to steganography based on the Catalan numbers in the design of medical software. The proposed solution is implemented in the Java programming language. In the experimental part, cryptanalysis and steganalysis of the proposed solution were given. Cryptanalysis is based on time and storage complexity, leaking information and machine learning-based identifcation of the encryption method. Also, steganalysis is based on the amount of information per pixel in stego image, approximate entropy and bit distribution in stego-images. Implementation of Encryption and Data Hiding in E-Health Application Muzafer H Saracevic https://orcid.org/0000-0003-2577-7927 University of Novi Pazar, Serbia. Aybeyan Selimi International Vision University, North Macedonia Selver Pepić Higher Technical Machine School of Professional Studies in Trstenik, Serbia