This book constitutes the proceedings of the satellite workshops held around the 21st International Conference on Applied Cryptography and Network Security, ACNS 2023, held in Kyoto, Japan, in June 2023.

The 34 full papers and 13 poster papers presented in this volume were carefully reviewed and selected from 76 submissions. They stem from the following workshops:

- 1st ACNS Workshop on Automated Methods and Data-driven Techniques in Symmetric-key Cryptanalysis (ADSC 2023)

- 5th ACNS Workshop on Application Intelligence and Blockchain Security (AIBlock 2023)

- 4th ACNS Workshop on Artificial Intelligence in Hardware Security (AIHWS 2023)

- 5th ACNS Workshop on Artificial Intelligence and Industrial IoT Security (AIoTS 2023)

- 3rd ACNS Workshop on Critical Infrastructure and Manufacturing System Security (CIMSS 2023)

- 5th ACNS Workshop on Cloud Security and Privacy (Cloud S&P 2023)

- 4th ACNS Workshop on Secure Cryptographic Implementation (SCI 2023)

- 4th ACNS Workshop on Security in Mobile Technologies (SecMT 2023)

- 5th ACNS Workshop on Security in Machine Learning and its Applications (SiMLA 2023)