{"id":432,"date":"2023-02-23T00:00:00","date_gmt":"2023-02-22T16:00:00","guid":{"rendered":"http:\/\/localhost:8092\/prolink-mrq-osdp\/"},"modified":"2026-07-30T16:05:05","modified_gmt":"2026-07-30T08:05:05","slug":"prolink-mrq-osdp","status":"publish","type":"post","link":"https:\/\/www.twpro-link.com\/en\/prolink-mrq-osdp\/","title":{"rendered":"\u201cThe Open Supervised Device Protocol (OSDP) \u2014 Why Does It Make Your Access Control More Secure?\u201d"},"content":{"rendered":"
\n\t\t\t\t
\n\t\t\t\t\t
\n\t\t\t\t
\n\t\t\t\t\t\t\t\t\t

In the next three articles, Mr.Q will systematically walk you through how communication protocols in access control systems affect their security.
This is Part One. Before we discuss how communication protocols affect access control system security, let's first understand which components affect the security of an access control system.
An access control system \u2014 in English, Physical Access Control System (abbreviated PACS, hereafter referred to as \u201caccess control system\u201d) \u2014 is a system that opens doors using various types of credentials (such as facial recognition, fingerprints, a mobile phone, or an access card). An access control system is made up of a variety of components. Below is a typical structural diagram:<\/p>

\u00a0<\/p>

\u00a0<\/p>

\u201cHow an Access Control System Works\u201d<\/span><\/strong><\/h2>

\"\u9580\u7981\u7cfb\u7d71\u7684\u5de5\u4f5c\u539f\u7406<\/p>

Figure 1: Access Control System Diagram<\/p>

\u00a0<\/p>

The front-end devices of a typical access control system consist of: access credentials (including access cards, fingerprint recognition, mobile apps, etc.), card readers, electric locks, exit buttons (for single-sided doors), door contact sensors, and so on. These front-end devices are all connected to the access controller via wiring and cables. On the back end of the access controller is the human-machine interface \u2014 the access control management software \u2014 which is usually connected over the network, though earlier controllers were sometimes connected via other means such as RS-485 or a serial port.<\/p>

A brief introduction to how access control works<\/p>

\u00a0<\/p>

\"\u57162<\/p>

Figure 2: Access Control Workflow Diagram<\/p>

\u00a0<\/p>

When someone swipes a card, the card number is sent to the access controller. The controller checks whether this card number has permission \u2014 if it does, the door opens, and the swipe record is sent over the network to the server for display and storage. If it does not have permission, the swipe is rejected and that information is uploaded instead.<\/p>

\u00a0<\/h2>

\u00a0<\/h2>

\u201cFactors Affecting Access Control System Security <\/span><\/strong>\u300f<\/span><\/strong><\/h2>

The overall workflow of an access control system is quite simple. So what factors should we consider when choosing a secure access control system?
Let's start with the architecture diagram below<\/p>

\u00a0<\/p>

\"\u57163<\/p>

Figure 3: Access Control System Architecture Diagram<\/p>

\u00a0<\/p>

During operation, the front end uses an access credential to swipe, the reader reads the card and sends the information to the local controller, which uploads the information to the main controller (*in some systems, the local controller is integrated into the main controller). After processing the information, the main controller both executes the door-opening action and passes the information on to the management software.
Every step here carries a security risk!<\/p>

\"\u57164<\/p>

Figure 4: Access Control System Risk Diagram<\/p>

\u00a0<\/p>

For example:
If the access card's security isn't high enough, it may be at risk of being cloned;
Information between the card reader and the local controller is transmitted via cable, so card data could be intercepted and subjected to a replay attack;
If the signals passed between the local controller and the main controller \u2014 including uploaded card data and downstream control commands \u2014 are hijacked by a hacker, false or tampered door-opening control signals could be sent; the main controller and the management software are connected via a network cable, so network data could be intercepted or tampered with, using a fake host to take control of the main controller. Today's access control systems have corresponding security solutions for each of these threats (see the diagram below):<\/p>

\"\u57165<\/p>

Figure 5: Access Control Security Countermeasures<\/p>

\u00a0<\/p>