Measuring Legal Readiness on Determination of Cyber Security Threats on Electronic System in Indonesia Arlina Permanasari {arlina.p@trisakti.ac.id} Universitas Trisakti, Jakarta, Indonesia Abstract. The number of cyber-attacks in Indonesia which has doubled since 2019 and reached 495,337,202 in 2020 needs to be followed up comprehensively, including the preparation of legal instruments. The Law No. 11 of 2008 on Information and Electronic Transactions and Government Regulation No. 82 of 2012 concerning the Implementation of Electronic Systems and Transactions are the basis documents for regulating cyber security and defence systems that still requires strategic and effective control, coordination and supervision. This paper discusses the readiness of legal instruments, which refers to the cyber security system as part of cyber defence. The discussion refers to the content analysis of national regulations on the cyber security. Keywords: Cyber security; electronic system; Indonesia 1 Introduction Since 2014, the internet technology has resulted in cyber-attacks,[1, p. 973] and still continue until now.[2] Today, cyber-attacks are still a debatable issue whether recognized as part of the use of armed force, and can provide support for military operations. A very phenomenal cyber-attack was cyber-attacks on November 20 and 23, 2010 in Iran. The Iranian military officially stated that the Stuxnet worm managed to cause a dangerous explosion at the uranium centre and damage Iran's nuclear facility at Natanz.[3, p. 376] These events have a real, significant impact and break the notion that cyber-attacks cannot have a physical impact. However, cyber-attacks occurred before the incident can also have a significant impact even though it does not result in a physical impact. A classic example is the cyber-attacks that took place in Georgia, Lithuania and Kyrgyzstan.[4, p. 237] At that time there were cyber- attacks in the form of DDoS and SQL injections causing harm on hundreds of websites. The situations behind the cyber-attacks in the three countries more or less make the intensity of cyber-attacks a threat that leads to cyber war.[5, p. 5] Moreover, the attack leads to areas that are very important for the state such as government, banking, health, security and national defence. This needs to be watched out for, among others, by preparing various legal instruments to anticipate cyber-attacks. This raises the main question that will be discussed in this paper, namely how is the readiness of Indonesian legal instruments in responding to the increasing number of cyber-attacks, which can pose a threat to the occurrence of cyber wars. LePALISSHE 2021, August 03, Malang, Indonesia Copyright © 2022 EAI DOI 10.4108/eai.3-8-2021.2315053