{'fraction_non_alphanumeric': 0.01834862385321101, 'fraction_numerical': 0.0, 'mean_word_length': 5.4605263157894735, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Demystifying ARM TrustZone TEE Client API using OP-TEE

Recently, sensitive information such as financial data and electronic payment systems have been stored in mobile devices. To protect important data, TEE technology has emerged, a trusty and safe execution environment. In particular, ARM TrustZone technology, which is mainly used in mobile, divides one physical processor into Normal World and Secure World to provide a safer execution environment. Many manufacturers have started using TrustZone technology, but existing commercial TEEs have limitations in conducting security research using TrustZone. Therefore, this paper shows how to use OP-TEE which is an open source project for implementing ARM TrustZone technology and TEE Client API that communicates with Trusted Application of TrustZone Secure World. To demystify TEE Client API, we implemented a simple trusted application for communication between Normal World and Secure World in OP-TEE OS using QEMU emulator.