# How Computers Use Hardware to Stop Software Piracy and Cracking > A 1982 hardware-based security system that prevents software from being copied or cracked by destroying sensitive data if the computer detects unauthorized access or execution. - **Patent:** US 4558176 - **Original title:** Computer systems to inhibit unauthorized copying, unauthorized usage, and automated cracking of protected software - **Owner:** Individual - **Granted:** 1985 - **Status:** Public domain (expired) - **Times cited:** 280 - **Field:** consumer_electronics, semiconductors, software ## What it does This patent describes a computer architecture designed to protect software by keeping it encrypted while in storage and only decrypting it for execution within a secure hardware environment. The system uses a 'violation recognition' mechanism that monitors where instructions are coming from in memory. If the processor attempts to execute code from an unauthorized memory region, a 'destruction means' triggers to wipe the execution key and register data, effectively killing the process before a cracker can analyze it. It also includes a 'handshake' mechanism that allows legitimate jumps between authorized code segments while still preventing unauthorized access to the protected memory regions. ## What it does NOT cover - Does not cover software-only copy protection schemes that lack the specific hardware-based destruction and translation mechanisms. - Does not cover general-purpose encryption methods that do not involve the hardware-level monitoring of memory regions for instruction execution. - Does not cover modern cloud-based license verification systems that rely on external servers rather than internal hardware state destruction. ## The clever bit The system treats the processor's own registers and execution keys as volatile assets that must be physically wiped the moment a memory boundary violation is detected, turning the hardware into a 'self-destructing' security perimeter. ## Real-world examples 1. Hardware-based DRM (Digital Rights Management) modules 2. Trusted Execution Environments (TEEs) in mobile processors 3. Secure Enclaves in modern CPUs ## Why it matters This patent represents an early attempt to move software security from the software layer to the hardware layer, anticipating modern concepts like Trusted Execution Environments (TEEs). It highlights the historical struggle to prevent 'automated cracking'—the use of software tools to reverse-engineer or bypass copy protection—by making the hardware itself an active participant in the security process. ## Frequently asked questions ### What does How Computers Use Hardware to Stop Software Piracy and Cracking cover? A 1982 hardware-based security system that prevents software from being copied or cracked by destroying sensitive data if the computer detects unauthorized access or execution. ### Who owns patent US 4558176? Individual owns this patent, granted in 1985. ### When does this patent expire? This patent has expired and is now in the public domain — anyone can use the invention freely. ### What is patent US 4558176 cited by? This patent has been cited by 280 later patents that build on its ideas. ### What problem does this patent solve? This patent represents an early attempt to move software security from the software layer to the hardware layer, anticipating modern concepts like Trusted Execution Environments (TEEs). It highlights the historical struggle to prevent 'automated cracking'—the use of software tools to reverse-engineer or bypass copy protection—by making the hardware itself an active participant in the security process. ### What does this patent NOT cover? Does not cover software-only copy protection schemes that lack the specific hardware-based destruction and translation mechanisms. **Full plain-English explainer:** https://patentbrief.org/patent/us/4558176/computer-systems-to-inhibit-unauthorized-copying-unauthorized-usage-and-automated-cracking-of-protected-software **Original patent:** https://patents.google.com/patent/US4558176 --- _Source: PatentBrief — https://patentbrief.org. Patent facts are from public records; the plain-English explanation is PatentBrief's._ ## Related patents Semantically similar inventions in the PatentBrief corpus: - [How External Hardware Keys Secure Digital Purchases and Downloads](https://patentbrief.org/patent/us/7404202/netflix-dvd-by-mail-queue) — A system using a physical hardware device to prove your identity to a server, allowing you to securely download and decrypt digital assets. - [Securing Data Storage Commands with Passcodes](https://patentbrief.org/patent/us/10102356/macos-dark-mode) — This patent describes a system for securely executing commands on data storage systems by requiring a generated passcode, which is based on user authentication and specific storage entity attributes. - [How a Local Server Decides to Save or Degrade Digital Content](https://patentbrief.org/patent/us/9934408/windows-information-protection) — A system that checks if incoming digital files are authentic, fake, or unknown, and then either saves them, rejects them, or lowers their quality accordingly. - [How Microsoft Protects Corporate Data on Employee Devices](https://patentbrief.org/patent/us/9430664/windows-defender-antivirus) — A system that lets companies remotely lock or delete specific work data on a phone or computer without wiping the user's personal files. - [How to Check if an AI Model Has Been Tampered With](https://patentbrief.org/patent/us/11544411/machine-learning-model-validation-and-authentication) — This patent describes a method to verify the integrity and authorized use of an artificial intelligence model by feeding it a special digital key and comparing its response to a known good one.