Patent 7784058

Derivative works

Defensive disclosure: derivative variations of each claim designed to render future incremental improvements obvious or non-novel.

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Derivative works

Defensive disclosure: derivative variations of each claim designed to render future incremental improvements obvious or non-novel.

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Defensive Disclosure and Prior Art Derivations for US 7,784,058

Document ID: DP-20260514-01
Publication Date: May 14, 2026
Subject: Derivative implementations and applications of user-mode, application-specific critical system elements as described in US Patent 7,784,058. This document is intended to enter the public domain as prior art.

Axis 1: Component & Architecture Substitution

Derivative 1.1: WebAssembly (WASM) Module as a Sandboxed Critical System Element

  • Enabling Description: This variation replaces the native shared library (.so or .dll) with a portable, sandboxed WebAssembly (WASM) module. An application, instead of linking against a native library, instantiates a WASM runtime (such as WASI) within its own process space. It then loads a .wasm file containing the Critical System Element (e.g., a TCP/IP stack or a file system driver written in Rust and compiled to WASM). The application communicates with the WASM CSE through a well-defined interface, and the WASM runtime enforces strict sandboxing, preventing the CSE from accessing unauthorized memory or system resources. The WASM module uses the WebAssembly System Interface (WASI) to make low-level calls to the underlying host kernel for fundamental operations like socket I/O, which are mediated by the host application's permissions. This approach provides cross-platform portability and enhanced security compared to native shared libraries.

  • Mermaid.js Diagram:

    graph TD
    subgraph "User Process: App A"
        App_A_Code["Application A Code"]
        WASM_Runtime_A["WASM Runtime (in-process)"]
        WASM_Module_A["TCP/IP Stack (network.wasm)"]
        
        App_A_Code -- "Instantiates & Calls" --> WASM_Runtime_A
        WASM_Runtime_A -- "Loads & Executes" --> WASM_Module_A
        WASM_Module_A -- "WASI Calls (e.g., sock_send)" --> WASM_Runtime_A
        WASM_Runtime_A -- "Mediated Access" --> Host_OS_Syscalls
    end

    subgraph "User Process: App B"
        App_B_Code["Application B Code"]
        WASM_Runtime_B["WASM Runtime (in-process)"]
        WASM_Module_B["Different TCP/IP Stack (network_v2.wasm)"]

        App_B_Code -- "Instantiates & Calls" --> WASM_Runtime_B
        WASM_Runtime_B -- "Loads & Executes" --> WASM_Module_B
        WASM_Module_B -- "WASI Calls" --> WASM_Runtime_B
        WASM_Runtime_B -- "Mediated Access" --> Host_OS_Syscalls
    end

    subgraph "Kernel Mode"
        Host_OS_Syscalls["Host OS Kernel (System Call Interface)"]
    end

Derivative 1.2: Unikernel-based Critical System Elements

  • Enabling Description: In this model, each SLCSE is packaged as a complete unikernel—a specialized, single-address-space machine image containing only the application logic and the necessary OS libraries. A lightweight, user-mode hypervisor or process loader, running in the context of the main application, loads and executes this unikernel CSE in a virtualized sandbox within the application's address space. For instance, an application requiring high-performance packet processing would load a net_unikernel image containing a specialized network stack (e.g., MirageOS, LING). Communication between the application and the unikernel CSE occurs via a shared memory interface (virtio-ring), eliminating system call overhead for data exchange. The user-mode loader is responsible for mapping device access (e.g., a raw network socket) from the host OS into the context of the unikernel.

  • Mermaid.js Diagram:

    sequenceDiagram
    participant App as Application
    participant Loader as User-Mode Loader
    participant CSE as Unikernel CSE
    participant Kernel as Host OS Kernel

    App->>Loader: Request CSE('network_stack')
    Loader->>Kernel: mmap(shared_memory)
    Loader->>Kernel: open(/dev/net/tun) for raw net access
    Kernel-->>Loader: Return file descriptor
    Loader->>CSE: Start unikernel_instance(shm_addr, net_fd)
    App->>CSE: Write packet data to shared memory
    CSE->>CSE: Process packet using own network stack
    CSE->>Loader: Use net_fd to send packet
    Loader->>Kernel: write(net_fd, packet_data)

Derivative 1.3: Hardware-Assisted Isolation using Secure Enclaves (Intel SGX)

  • Enabling Description: The SLCSE is compiled to run inside a hardware-based secure enclave, such as Intel SGX or AMD SEV. When an application is loaded, a special loader module initiates the enclave and loads the SLCSE code and data into the protected memory region. The application communicates with the SLCSE through a trusted "ECALL" interface, and the SLCSE communicates with the outside world through "OCALLs" that exit the enclave to request services (like network I/O) from the untrusted host application and OS. This provides cryptographic guarantees of isolation and integrity, ensuring that even a compromised host OS cannot tamper with the state of the critical system element. For example, a cryptographic key manager SLCSE could run within an enclave, guaranteeing that private keys are never exposed in plaintext to the main application or the OS.

  • Mermaid.js Diagram:

    graph TD
    subgraph "CPU (Hardware Boundary)"
        subgraph "User Process (Untrusted)"
            App["Application Code"]
            OS_Proxy["OS Proxy Lib"]
            App -- "ECALL (Trusted Call)" --> SGX_Enclave
        end
        
        subgraph SGX_Enclave [Secure Enclave (Encrypted Memory)]
            SLCSE["SLCSE Code & Data (e.g., SSL/TLS Stack)"]
            SLCSE -- "OCALL (Untrusted Call)" --> OS_Proxy
        end
    end

    subgraph Kernel
        KernelDriver["OS Kernel"]
    end

    OS_Proxy -- "System Call" --> KernelDriver

Axis 2: Operational Parameter Expansion

Derivative 2.1: Critical System Elements for Hard Real-Time Systems (RTOS)

  • Enabling Description: This variation is implemented in a hard real-time operating system (RTOS) like QNX or VxWorks. A high-priority control loop task (e.g., for a robot arm) requires deterministic network communication. To avoid jitter from the system's general-purpose TCP/IP stack, this task dynamically links its own instance of a real-time, lightweight UDP stack as an SLCSE. This SLCSE is designed with lock-free data structures and a pre-allocated memory pool to ensure all operations complete within a bounded time (worst-case execution time). It communicates with the network device driver via a zero-copy, shared-memory queue, bypassing the kernel's standard socket layer. This isolates the timing behavior of the critical task from all other lower-priority network activities on the system.

  • Mermaid.js Diagram:

    stateDiagram-v2
    direction LR
    [*] --> Idle
    
    state Task_A_Context {
        direction LR
        state "High Priority Task (Robot Control)" as HPT
        state "RT-UDP Stack SLCSE" as RT_UDP
        HPT --> RT_UDP : send_data()
        RT_UDP --> HPT : return (WCET < 20us)
    }
    
    state Task_B_Context {
        direction LR
        state "Low Priority Task (Logging)" as LPT
        state "Kernel TCP/IP Stack" as K_TCP
        LPT --> K_TCP : send_log()
        K_TCP --> LPT : return (non-deterministic)
    }

    Idle --> Task_A_Context : Timer Interrupt
    Task_A_Context --> Idle : Execution Complete
    Idle --> Task_B_Context : Idle Time
    Task_B_Context --> Idle : Execution Complete

Derivative 2.2: Ephemeral CSEs for Function-as-a-Service (FaaS) Platforms

  • Enabling Description: In a serverless/FaaS environment, each function execution requires isolated access to a database. Instead of a shared connection pool, the FaaS runtime injects a purpose-built, ephemeral database connection SLCSE into the function's execution environment upon invocation. This SLCSE is pre-configured with the specific credentials and connection string for that function. It establishes a connection, manages transactions, and is completely destroyed when the function terminates. This architecture provides perfect isolation between function invocations, preventing credential leakage or transactional state interference. The SLCSE can be optimized for rapid startup and teardown, a critical performance metric in FaaS platforms.

  • Mermaid.js Diagram:

    sequenceDiagram
    participant FaaS_Orchestrator
    participant FaaS_Worker
    participant Function_Instance
    participant DB_SLCSE as "Ephemeral DB SLCSE"
    participant Database

    FaaS_Orchestrator->>FaaS_Worker: InvokeFunction('myFunc')
    FaaS_Worker->>Function_Instance: Create Process
    FaaS_Worker->>DB_SLCSE: Instantiate and Inject
    Function_Instance->>DB_SLCSE: getConnection()
    DB_SLCSE->>Database: Authenticate & Connect
    Database-->>DB_SLCSE: Connection Handle
    DB_SLCSE-->>Function_Instance: Return Handle
    Function_Instance->>DB_SLCSE: Execute Query
    DB_SLCSE->>Database: Run SQL
    Database-->>DB_SLCSE: Results
    DB_SLCSE-->>Function_Instance: Return Results
    Function_Instance-->>FaaS_Worker: Execution Complete
    FaaS_Worker->>DB_SLCSE: Terminate & Destroy
    FaaS_Worker->>Function_Instance: Destroy Process

Axis 3: Cross-Domain Application

Derivative 3.1: Automotive - ADAS vs. In-Vehicle Infotainment (IVI)

  • Enabling Description: An automotive computing platform based on Automotive Grade Linux runs two applications with different safety requirements: a safety-critical ADAS application (ASIL D) and a non-critical IVI application (ASIL B). Both need access to the vehicle's CAN bus. The ADAS application links a certified, read-only, statically-analyzed CAN bus driver SLCSE that has been formally verified. The IVI system links a separate, full read-write CAN bus driver SLCSE that allows it to send diagnostic or control messages. Both SLCSE instances communicate with a kernel-level resource manager that arbitrates physical access to the CAN controller hardware, ensuring the ADAS application's messages are always prioritized and that the IVI application cannot send messages that would interfere with critical vehicle functions.

  • Mermaid.js Diagram:

    graph TD
    subgraph "ADAS Process (ASIL D)"
        ADAS_App["ADAS Logic"]
        CAN_SLCSE_RO["Certified Read-Only CAN Stack"]
        ADAS_App --> CAN_SLCSE_RO
    end

    subgraph "IVI Process (ASIL B)"
        IVI_App["Infotainment UI"]
        CAN_SLCSE_RW["Read-Write CAN Stack"]
        IVI_App --> CAN_SLCSE_RW
    end
    
    subgraph "Kernel Mode"
        Kernel_Arbiter["CAN Bus Kernel Arbiter"]
        CAN_HW["CAN Bus Hardware"]
        Kernel_Arbiter --> CAN_HW
    end

    CAN_SLCSE_RO -- "High-Priority Queue" --> Kernel_Arbiter
    CAN_SLCSE_RW -- "Low-Priority Queue" --> Kernel_Arbiter

Derivative 3.2: Aerospace - Modular Flight Control Systems

  • Enabling Description: An Integrated Modular Avionics (IMA) system hosts two distinct applications on a single processing module: a Flight Management System (FMS) and an Autopilot system. Both communicate over an ARINC 429 data bus. To ensure partitioning, the FMS application links arinc429_fms.so, an SLCSE configured only for the specific ARINC 429 labels relevant to flight planning. The Autopilot application links arinc429_ap.so, a different SLCSE configured for labels related to flight surface actuation. A kernel-level driver manages the physical ARINC 429 transceiver, but it exposes separate device contexts to each SLCSE, which enforce hardware-based label filtering. A write attempt by the FMS application using an Autopilot label will be rejected by the kernel driver, providing robust fault containment compliant with DO-178C standards.

  • Mermaid.js Diagram:

    classDiagram
    direction LR
    class FMS_Application {
        +executeFlightPlan()
    }
    class Autopilot_Application {
        +stabilizeAircraft()
    }
    class ARINC429_FMS_SLCSE {
        <<Library>>
        -allowed_labels: Set<Labels>
        +transmit(label, data)
    }
    class ARINC429_AP_SLCSE {
        <<Library>>
        -allowed_labels: Set<Labels>
        +transmit(label, data)
    }
    class Kernel_ARINC429_Driver {
        -device_context: Map<Process, Config>
        +register(process, config)
        +write(process, label, data)
    }

    FMS_Application ..> ARINC429_FMS_SLCSE : links
    Autopilot_Application ..> ARINC429_AP_SLCSE : links
    ARINC429_FMS_SLCSE ..> Kernel_ARINC429_Driver : uses
    ARINC429_AP_SLCSE ..> Kernel_ARINC429_Driver : uses

Axis 4: Integration with Emerging Technology

Derivative 4.1: AI-Driven Dynamic CSE Optimization

  • Enabling Description: A database application is instrumented with a monitoring agent. An AI/ML model, trained on performance counter data (e.g., I/O latency, cache hit rates), analyzes the application's workload in real-time. If the model detects a shift from a transactional (OLTP) to an analytical (OLAP) workload, it predicts that a different file system layout or caching strategy would be more performant. It instructs a control plane to trigger a hot-swap of the application's file system SLCSE. The system quiesces I/O, unlinks the current fs_oltp.so library, and dynamically links a new fs_olap.so library that implements a columnar storage access pattern. This dynamic, AI-driven adaptation optimizes performance without restarting the application.

  • Mermaid.js Diagram:

    sequenceDiagram
    participant App as Database App
    participant Agent as Monitoring Agent
    participant AI_Model as AI/ML Model
    participant Controller as Control Plane
    
    loop Real-time
        App->>Agent: Stream Perf. Counters
        Agent->>AI_Model: Send Metrics
        AI_Model->>AI_Model: Analyze Workload
        alt Workload Shift Detected
            AI_Model->>Controller: Recommend CSE: 'fs_olap.so'
            Controller->>App: Signal Quiesce I/O
            Controller->>App: dlclose('fs_oltp.so')
            Controller->>App: dlopen('fs_olap.so')
            Controller->>App: Signal Resume I/O
        end
    end

Derivative 4.2: Blockchain-Verified CSE Provenance

  • Enabling Description: In a regulated environment (e.g., medical devices), software integrity is paramount. Before an application is allowed to load, a trusted loader module computes the cryptographic hash of the designated SLCSE file (e.g., dicom_parser_v3.1.so). It then queries a private blockchain/distributed ledger using the SLCSE's name and version as a key. The transaction record on the blockchain contains the official, vendor-certified hash for that library version. If the computed hash matches the hash on the ledger, the loader proceeds to link the library. If not, the application launch is aborted, and an immutable audit event is logged to the blockchain, preventing the execution of tampered or unauthorized critical system code.

  • Mermaid.js Diagram:

    graph TD
    A[Start Application Load] --> B{Compute Hash of SLCSE file};
    B --> C{Query Blockchain for Certified Hash};
    C --> D{Hashes Match?};
    D -- Yes --> E[Link SLCSE & Continue];
    D -- No --> F[Abort Load & Log Audit Event];
    F --> G[End];
    E --> G[End];

Axis 5: The "Inverse" or Failure Mode

Derivative 5.1: Graceful Degradation via Fallback CSE

  • Enabling Description: A web server application links a high-performance, feature-rich network stack SLCSE (http_stack_accel.so) that uses kernel-bypass features. A health-monitoring thread within the application periodically checks the sanity of this SLCSE. If the health check fails (e.g., a memory corruption is detected), the monitor triggers a graceful fallback. It uses the dlsym and dlopen APIs to dynamically re-route the application's function pointers for send(), recv(), etc., from the failed SLCSE to a pre-loaded, simple, and robust fallback SLCSE (http_stack_safe.so). This safe version uses standard, stable kernel system calls. The application continues to run, serving basic requests with higher latency, instead of crashing completely.

  • Mermaid.js Diagram:

    stateDiagram-v2
    state "Running (High Performance)" as HP
    state "Running (Degraded Mode)" as DM
    state "Crashed" as CR

    [*] --> HP : Initial Load
    HP: Uses `http_stack_accel.so`

    HP --> DM : Health Check Fails
    DM: Re-links to `http_stack_safe.so`

    HP --> CR : Unhandled Exception
    DM --> HP : Manual Reset / Recovery

Combination Prior Art Scenarios with Open-Source Standards

  1. Combination with Docker/OCI and LD_PRELOAD: An OCI-compliant runtime like runc is modified to accept a custom annotation in the config.json file, specifying an application-specific network stack SLCSE. When creating the container, the runtime uses the LD_PRELOAD environment variable within the new container's namespace to force the application to load this specified library (e.g., LD_PRELOAD=/opt/lib/fast-stack.so). This fast-stack.so implements standard socket APIs but directs traffic to a user-mode network device (like AF_XDP), bypassing the kernel's network stack for that container only. This provides container-specific network behavior on a shared host kernel.

  2. Combination with Kubernetes and a Service Mesh Sidecar (Istio): The Istio service mesh injects its proxy (Envoy) not as a separate container but as an SLCSE (libenvoy.so) directly into the application's pod. The Pod spec includes a field for the Envoy configuration. The Kubelet, via a custom Container Runtime Interface (CRI) implementation, mounts the library and config into the container and uses dynamic linking mechanisms to load it. The library overrides standard networking calls (connect, send, recv) to transparently apply all mTLS encryption, traffic routing, and telemetry policies within the application's own process, eliminating the localhost network hop and reducing latency.

  3. Combination with QEMU/KVM and VirtIO: A guest VM running on a KVM hypervisor is provisioned with a standard para-virtualized VirtIO network device. A high-performance computing (HPC) application running inside the guest, however, requires lower latency. The application links a custom libvirtio-net-user.so SLCSE. This library communicates with a special character device exposed by the guest's VirtIO driver. Using ioctl calls, it maps the VirtIO device's virtqueues directly into the application's user-mode address space. The application can now place network packets directly onto the virtqueue and signal the hypervisor via an eventfd, completely bypassing the guest kernel's network stack for all its data path operations.

Generated 5/14/2026, 12:46:51 PM