If the drawings are copied away, the company will have to drink from the northwest. I have been working in data security for more than 20 years, and I have seen too many bosses return to pre-liberation overnight because of a few CAD drawings. Don't get me started talking about fancy firewalls. In the eyes of insiders, the core drawings are just like their own backyard, and they can be taken wherever they want.

Today I’m going to talk to you from the bottom of my heart about how to give these baby blueprints some of the most effective locks. The following 4 methods have all been personally verified by me for clients, and they are designed to treat all kinds of "take it and leave it alone".

4 hard-core methods for encrypting CAD drawings, bosses please copy them directly

1. Deploy the Insight Eye MIT system

Don't think that installing software is a hassle. This thing is an "invisible stamp" on the company's drawings. The core logic is just one sentence: drawings can be used casually within the company, but when they go out of the company, they become "bricks".

1. Transparent encryption, employees don’t even know they are locked : This is the most outrageous operation. When employees open CAD drawings and modify drawings on their computers, the process is exactly the same as before, without any sense of encryption. Once he wants to use WeChat to send it to others, or copy it to a USB flash drive and take it home, the file will be a bunch of garbled characters in his hands. This is called "non-sensory protection". The biggest advantage is that it does not delay work and the boss does not need to keep an eye on him every day.

2. Outsourcing control, installing "timers" on partners' drawings” : Many times drawings must be sent to suppliers or Party A. This software can generate an encrypted outgoing package. You can set this package to be opened only on a certain computer, only a few times, or automatically destroyed after a few days. The other party has to enter a password to open it, and even needs your authorization. This completely eliminates the possibility of the drawings being resold again.

3. Authority is isolated, and core departments also have to "keep a hand"” : Don’t think it’s safe inside. Why can the sales department see the pictures drawn by the design department? This system can accurately divide people's permissions. You have set it so that only a few core engineers have permission to open the final drawing. Even if others get the file, the system will prompt "You do not have permission to view it." Cut off the chain of internal leaks at the source.

4. During resignation and handover audit, you can find out who took away the drawings immediately : The biggest fear is that core employees will leave and take away several years of hard work. This system records the access, copy, and printing of each file throughout the process. If there is a real dispute, just pull out the backend audit log, and it will be clear who, when, and by what method touched the drawings. It is both a deterrent and evidence.

2. Hardware dongle (physical lock)

This trick is more old school, but still effective. Equip the core drawing file or the software itself with a hardware lock similar to a USB flash drive. This "dog" must be plugged in when the software is running. If it is unplugged, it cannot be saved or opened.

Floor effect : Suitable for extremely sensitive design software used by a few core experts. The disadvantage is that if the "dog" is lost or broken, the work will stop, and the management cost is high. It is suitable as the final "ballast stone" but not suitable for full-scale promotion.

3. Convert drawings to PDF and add dynamic watermarks

Many companies want to save trouble by converting CAD into PDF and sending it out. If you want to have fun, you have to make a fuss about PDF. When printing or taking screenshots, a watermark will automatically appear on the background of the drawing, showing "current operator name + job number + date and time".

Floor effect : The core of this method of "beware of gentlemen, not villains" is psychological shock. Employees know that they can send screenshots of themselves to others, and their job numbers are clearly displayed on the background of the screenshots. Once the drawings are leaked, the first person to be held accountable is yourself. Low cost, quick results, suitable for communication of non-core but sensitive design solutions.

4. Establish a “zero trust” network isolation zone

Separate the core design department and physically disconnect it from the network. All drawings can only be stored on the internal server. The computer at the design station is not connected to the external network. All U-ports are blocked. Even the mobile phone must be handed over to the cabinet outside the door.

Floor effect : The most primitive, the crudest, but also the most effective. Many core departments of military and heavy industry companies still use this trick. The disadvantage is that the experience is extremely poor, employees feel like they are in jail, recruitment is difficult, and the turnover rate is high. If the value of the drawings is not high enough to be "worthy of jail time", it is generally not recommended to try it easily, it is too anti-human.

To sum up : Don’t expect a single method to prevent all ghosts. What really works is the combination of "system + technology" like the Insight Eye MIT system, which not only ensures efficiency, but also minimizes the risk of leaks.

Source of this article: Enterprise Data Security Protection Alliance, Internal Risk Control Research Institute
Leading expert: Chen Guodong
Editor in charge: Liu Jingyi
Last updated: March 27, 2026