{
  "patent_number": "US 4558176",
  "country": "US",
  "title": "How Computers Use Hardware to Stop Software Piracy and Cracking",
  "original_title": "Computer systems to inhibit unauthorized copying, unauthorized usage, and automated cracking of protected software",
  "summary": "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.",
  "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."
  ],
  "filed": "1982-09-20",
  "granted": "1985-12-10",
  "expires": "2002-12-10",
  "status": "expired",
  "holder": "Individual",
  "holder_url": "https://patentbrief.org/company/individual",
  "inventors": [
    {
      "name": "Mark G. Arnold",
      "url": "https://patentbrief.org/inventor/mark-g-arnold"
    },
    {
      "name": "Mark D. Winkel",
      "url": "https://patentbrief.org/inventor/mark-d-winkel"
    }
  ],
  "times_cited": 280,
  "tags": [
    "consumer_electronics",
    "semiconductors",
    "software"
  ],
  "abstract": "A method and apparatus are provided for inhibiting unauthorized copying, unauthorized usage and automated cracking of proprietary software used in computer systems. The computer systems execute protected programs, which are protected by encapsulation and/or encryption. To provide security against unauthorized copying of software, means are provided that detect and inhibit automated cracking of protected programs. These means will destroy or make inaccessible information in the CPU during conditions when automated cracking could occur. These means will also store interrupt contexts in secret to prevent implementation of automated cracking. Additional features may be provided to allow operation as a general purpose computer system, where protected programs are distributed using public key cryptography and a means is provided to convert from this distribution form to the protected execution form.",
  "url": "https://patentbrief.org/patent/us/4558176/computer-systems-to-inhibit-unauthorized-copying-unauthorized-usage-and-automated-cracking-of-protected-software",
  "markdown_url": "https://patentbrief.org/patent/us/4558176/computer-systems-to-inhibit-unauthorized-copying-unauthorized-usage-and-automated-cracking-of-protected-software/md",
  "google_patents_url": "https://patents.google.com/patent/US4558176",
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}