Access Control

Secure MQTT Implementations – TLS, Authentication, and Access Control for IoT Networks

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Translation: https://www.javacodegeeks.com/2025/09/secure-mqtt-implementations-tls-authentication-and-access-control-for-iot-networks.html MQTT has become the de facto standard protocol for IoT communication: lightweight, reliable, and designed for resource-constrained devices. However, while MQTT simplifies communication between devices, it does not inherently provide security guarantees. Without proper safeguards, your IoT network may be vulnerable to eavesdropping, spoofing, or unauthorized access. This article will explore how to … Read more

5-Day Crash Course on Linux for Information Security Engineer Exam Preparation

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Understanding your needs, Linux system security is an important assessment content in the Information Security Engineer examination. I have designed a 5-day Linux crash course closely aligned with the exam points, incorporating analyses of past exam questions to help you prepare efficiently. To prepare for the exam, knowledge related to Linux may appear in multiple-choice … Read more

Understanding AOC, DAC, ACC, and AEC Cables in Data Centers

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Previously, we wrote an article about the NVL72 interconnection scheme. Some users in the community requested a further explanation of what these different cables in data centers mean. Let’s review where optical connections and copper connections are used in the GB200 standard. The abandoned NVL72 optical interconnection scheme regarding the GB200 architecture and interconnections has … Read more

Comprehensive Guide to Hardening Kali Linux: From Basic Protection to Advanced Defense Strategies

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Comprehensive Guide to Hardening Kali Linux: From Basic Protection to Advanced Defense Strategies

1. Core Logic and Industry Background of System Hardening In the global cybersecurity threat landscape of 2025, APT attacks and ransomware supply chain incidents are frequent. As a standard platform for penetration testing and security research, the hardening of Kali Linux needs to establish a closed-loop system of “proactive defense – dynamic monitoring – rapid … Read more

Detailed Configuration of hosts.allow and hosts.deny for Access Control in Linux to Enhance System Security

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Detailed Configuration of hosts.allow and hosts.deny for Access Control in Linux to Enhance System Security

In daily Linux system administration, we often need to control which hosts can access our services. Today, we will provide a detailed introduction to two powerful access control files: <span>hosts.allow</span> and <span>hosts.deny</span>, to enhance system security. 1. Introduction to hosts.allow and hosts.deny Files These two files are configuration files for TCP Wrappers, used to control … Read more

Do Smart Locks Need Encryption Chips?

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Do Smart Locks Need Encryption Chips?

Smart locks, as an important component of the smart home ecosystem, bring great convenience to users’ daily lives, but the accompanying security risks cannot be ignored. In the field of smart locks, the ease of copying card keys is a prominent issue and security concern. In the field of smart access control and locks, the … Read more

PID Closed-Loop Control Experiment Based on STM32F1 Series: Potentiometer Knob Drive

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PID Closed-Loop Control Experiment Based on STM32F1 Series: Potentiometer Knob Drive

We use ADC2 to implement the potentiometer knob. Potentiometer Knob Initialization Code.c void PotentiometerKnob_Init(void){ /* Enable clock */ RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC2, ENABLE); // Enable ADC2 clock RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE); // Enable GPIOA clock /* Set ADC clock */ RCC_ADCCLKConfig(RCC_PCLK2_Div6); // Select clock division 6, ADCCLK = 72MHz / 6 = 12MHz /* GPIO initialization */ GPIO_InitTypeDef GPIO_InitStructure; GPIO_InitStructure.GPIO_Mode … Read more

Analysis of Access Control Mechanisms for Smart Watches in Compliance with EN 18031 Standards

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Analysis of Access Control Mechanisms for Smart Watches in Compliance with EN 18031 Standards

In the era of rapid development in information technology, smart watches have become a typical representative of the wave of intelligence. Traditional watches are limited to basic services such as time display and timing, while smart watches not only retain core functions but also expand into health features such as heart rate monitoring and exercise … Read more

Learning PID – Implementation of Speed Control for Stepper Motors

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Learning PID - Implementation of Speed Control for Stepper Motors

Overview of the Principle A stepper motor is a motor driven by digital signals, one of its main advantages being its excellent open-loop control capability, where the control system does not require sensors and corresponding circuits to feedback motor information. Under conditions where the load is not overloaded and the pulse frequency is appropriate, the … Read more

Industrial IoT Encryption Gateway: The Key Line of Defense for Industrial Data Security

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Industrial IoT Encryption Gateway: The Key Line of Defense for Industrial Data Security

In today’s booming Industrial Internet of Things (IIoT), the interconnection of industrial devices has become the norm, with massive amounts of data frequently transmitted between devices and the cloud. However, the security of data transmission faces numerous challenges, such as data leakage, tampering, and unauthorized access, which can cause significant losses in industrial production. The … Read more