This volume constitutes selected papers presented at the Third International Symposium on Emerging Information Security and Applications, EISA 2022, held in Wuhan, China, in October 2022. Due to COVID-19, EISA 2022 was held fully online. The 13 full papers presented in this volume were thoroughly reviewed and selected from the 35 submissions. They present a discussion on the emerging techniques, theories and applications to enhance information and application security in practice.