This book of Lecture Notes in Networks and Systems contains accepted papers presented at the 16th International Conference on Computational Intelligence in Security for Information Systems (CISIS 2023) and the 14th International Conference on EUropean Transnational Education (ICEUTE 2023). These conferences were held in the beautiful city of Salamanca, Spain, in September 2023. The aim of the CISIS 2023 conference is to offer a meeting opportunity for academic and industry-related researchers belonging to the various, vast communities of computational intelligence, information security, and data mining. The need for intelligent, flexible behavior by large, complex systems, especially in mission-critical domains, is intended to be the catalyst and the aggregation stimulus for the overall event. The aim of ICEUTE 2023 conference is to offer a meeting point for people working on transnational education within Europe. It provides a stimulating and fruitful forum for presenting and discussing the latest works and advances on transnational education within European countries.