The 25th Australasian Conference on Information Security and Privacy (ACISP) is held as virtual online conference on 30 Nov - 02 Dec 2020. During ACISP 2020, there are one lecture, four keynotes, ten sessions (Signature, Symmetric Cipher, Post-Quantum Cryptography, Network Security and Blockchain, Attack, Privacy, Cryptographic Primitives, Mathematical Foundation, Machine Learning Security, Short Papers) and one discussion (about Blockchain). Basically, every presenter has 5 minutes for introducing top structure of their research work and 5 minutes for Q&A. It is difficult to learn the details from such short presentations. But we can still learn a lot from lectures, keynotes or the discussion.