Method and system for client-side artificial intelligence processing with end-to-end encryption in web browsers

1 . A method for performing artificial intelligence operations on encrypted data within a web browser while maintaining end-to-end encryption, the method comprising: a) validating security headers including Cross-Origin-Opener-Policy (COOP) set to “same-origin”, Cross-Origin-Embedder-Policy (COEP) set to “require-corp”, Strict-Transport-Security with max-age ≥31536000, and Origin Isolation as enforced by a browser policy or an equivalent mechanism, collectively defining a secure context prerequisite; wherein failure on any prerequisite causes immediate termination and an audited REJECT event following a PASS/FAIL enforcement flow; b) establishing a secure browser execution environment only after successful validation in step (a), with memory alignment using 64-byte cache-aligned buffers matching a central processing unit (CPU) cache line size and by allocating unmapped memory regions that act as guard pages, causing detectable access faults intercepted by a security monitor; c) implementing dual-phase WebAssembly (WASM) import validation comprising load-time pattern matching prohibiting categories including network operations, Document Object Model (DOM) access, code evaluation, and persistent storage Application Programming Interfaces (APIs), while permitting restricted mathematical, Single Instruction, Multiple Data (SIMD), and Graphics Processing Unit (GPU)-related imports; and instantiation-time attestation generation cryptographically binding validated import set to an audit chain; d) initiating a plaintext exposure timer immediately upon decryption and enforcing a maximum plaintext window T≤1000 milliseconds, triggering an emergency wipe sequence completing within 15 milliseconds upon timeout violation, and generating an audited violation event according to a PASS/FAIL flow; e) executing artificial intelligence inference entirely client-side and, when available, performing zero-copy CPU to GPU tensor buffer transfer while prohibiting plaintext persistence in a GPU memory and enforcing mandatory GPU buffer clearing within 100 milliseconds of kernel execution completion, throwing a SecurityError upon clearing timeout; f) re-encrypting all inference outputs immediately upon processing completion and prior to any persistence or transmission beyond the secure execution environment; g) performing a cryptographically verified multi-pass clearing of all plaintext buffers compliant with National Institute of Standards and Technology Special Publication (NIST SP) 800-88, including random-zero-random passes and verification by XOR or digest comparison before releasing memory; h) appending an event record to a keyed hash audit chain defined by H n =HMAC_k(H n-1 ∥ event ∥ nonce ∥ timestamp), enabling tamper-evident verification of decryption, inference, re-encryption, and wiping operations; i) wherein decryption keys are non-extractable Web Crypto API keys bound to WebAuthn/Fast Identity Online (FIDO) credentials, rotated on a schedule to provide forward secrecy, and accessible only within secure contexts satisfying the prerequisites of step (a); wherein said steps collectively transform the web browser from a standard execution environment into a secure Artificial Intelligence (AI) processing environment providing time-bounded plaintext exposure, verified memory clearing, and cryptographic audit capabilities not provided by a conventional browser architecture and security policies.

2 . The method of claim 1 , wherein T=800 milliseconds for healthcare diagnostic assistance with Health Insurance Portability and Accountability Act (HIPAA) compliance and T=100 milliseconds for real-time translation services.

3 . The method of claim 1 , wherein the cryptographically verified multi-pass clearing comprises exactly three passes with Pass 1 using cryptographically secure random data, Pass 2 using zeros, Pass 3 using new cryptographically secure random data, and a verification pass computing XOR between Pass 1 and Pass 3 with threshold-based validation requiring at least 40% bit difference.

4 . The method of claim 1 , wherein the security monitor performs dual-phase validation comprising load-time regex pattern matching against whitelist and blacklist, and instantiation-time verification generating a signed attestation artifact that is recorded in the audit chain with a timestamp, a validated imports list, a rejected imports list, and a Secure Hash Algorithm (SHA)-256 module hash.

5 . The method of claim 4 , wherein the signed attestation artifact recorded in the audit chain comprises timestamp of validation with microsecond precision via performance.now( ), complete list of validated imports that matched whitelist patterns, complete list of rejected imports that matched blacklist patterns with rejection reason codes, SHA-256 hash of the WebAssembly module binary for module identity verification, digital signature using ECDSA-P256 with session-specific signing key derived via HKDF-SHA256, nonce value preventing replay attacks, and chain linkage to previous attestation events via HMAC binding.

6 . The method of claim 1 , wherein the audit chain is exportable in a JavaScript Object Notation (JSON) format comprising fields comprising timestamp, event_type, nonce, prev_hash, hash, and verification_status, and/or Comma-Separated Value (CSV) format with headers comprising timestamp, event_type, nonce, prev_hash, and hash for regulatory compliance documentation.

7 . The method of claim 6 , wherein the JSON format for the audit chain comprises schema version field “1.0” for compatibility tracking, events array containing ordered sequence of audit events, each event object containing fields {id, timestamp, event_type, nonce, prev_hash, hash, verification_status, metadata}, metadata object containing operation-specific details including {modelId, plaintextDurationMs, dataHash, operationType, securityLevel}, verification_hash field containing SHA-256 of entire audit chain for integrity checking, signature field containing ECDSA signature of verification_hash for non-repudiation, and export_timestamp field recording when export was generated for forensic timeline reconstruction.

8 . The method of claim 1 , wherein the WebAssembly import control system comprises a whitelist implemented as pattern matching for safe-operation patterns including Math., Memory., Table., SIMD., WebGL., WebGPU., Performance.now, Crypto.getRandomValues, and Worker.postMessage with ArrayBuffer transfer semantics or equivalent zero-copy mechanisms; a blacklist implemented as pattern matching for disallowed patterns including DOM object access patterns, file system API patterns, network primitive patterns (fetch, XMLHttpRequest, WebSocket, WebRTC), dynamic code evaluation patterns (eval, Function, importScripts), timer primitive patterns prone to side-channels (setTimeout, setInterval), and direct storage API patterns (localStorage, sessionStorage, indexedDB); SecurityError thrown immediately upon detecting any blacklisted import with immediate process termination; and audit chain entry recording each validation with timestamp, import pattern matches, and validation result.

9 . The method of claim 1 , wherein the bounded plaintext window enforcement comprises a PlaintextWindowEnforcer class with configurable maxWindow parameter defaulting to 1000 ms, decryption timestamp recorded with microsecond precision via performance.now( ), enforcement timer triggered at (maxWindow−10 ms) as safety margin, monitoring loop executing every 100 ms via requestAnimationFrame checking elapsed time, warning event generated at 90% threshold (900 ms for 1000 ms window), emergency wipe sequence executing within 15 ms upon timeout violation, and audit events generated for warning threshold, timeout violation, and successful completion.

10 . The method of claim 1 , wherein the cryptographically verified multi-pass memory clearing comprises Pass 1 filling buffer with cryptographically secure random data via crypto.getRandomValues( ), Pass 2 overwriting buffer with zeros using TypedArray.fill(0), Pass 3 filling buffer with new cryptographically secure random data, XOR verification computing bitwise XOR between Pass 1 and Pass 3 random patterns, verification threshold requiring at least 40% of bits to differ confirming successful clearing, audit event recording pass count, verification method, bit-difference percentage, and pass/fail status, and ArrayBuffer detachment with reference nulling after successful verification.

11 . The method of claim 1 , wherein the HMAC audit chain comprises genesis block H o =SHA-256(masterKey+Date.now( )), event counter incrementing monotonically from 1, nonce generation using crypto.getRandomValues(new Uint8Array(16)) for each event, event data structure containing {id, type, modelId, plaintextDurationMs, dataHash, operationType, timestamp}, session key derivation via HKDF-SHA256 from master key, session key rotation every 86400000 ms (24 hours) for forward secrecy, chain verification requiring O(n) time for n events with constant-time comparison preventing timing attacks, and export format supporting both JSON with schema version 1.0 and CSV with headers for regulatory compliance.

12 . The method of claim 1 , wherein the GPU acceleration comprises detecting WebGPU availability via navigator.gpu?.requestAdapter( ), creating GPU buffer with exact size match to CPU tensor dimensions, zero-copy transfer via ArrayBuffer.transfer( ) or equivalent zero-copy view/queue mapping when available or memory mapping via gpuBuffer.getMappedRange( ) without intermediate allocation, kernel execution on GPU compute pipeline, mandatory secureClear( ) within 100 ms of kernel completion filling GPU buffer with cryptographically secure random data, SecurityError thrown if clearing exceeds 100 ms timeout, buffer.destroy( ) call ensuring no persistent GPU storage, fallback to WebGL providing 5-25× acceleration if WebGPU unavailable, and performance monitoring tracking actual acceleration factors against expected ranges.

13 . The method of claim 1 , wherein the non-extractable key management comprises key generation via crypto.subtle.generateKey( ) with extractable parameter explicitly set to false preventing key export, WebAuthn credential creation binding key to FIDO2 authenticator hardware, key usage restricted to [‘encrypt’, ‘decrypt’] operations only via Web Crypto API usage parameter, key accessible only in secure contexts with validated COOP/COEP/HSTS/Origin Isolation headers, rotation schedule triggering new key generation every 2592000000 ms (30 days), key derivation using HKDF-SHA256 for forward secrecy ensuring old session keys cannot decrypt new data, old keys retained for decryption of historical data but not permitted for new encryption operations, and audit chain recording all key generation events, rotation events, and usage events with timestamps.

14 . The method of claim 1 , wherein the emergency wipe sequence comprises detection of timeout violation when T_current−T_start≥T_max at monitoring loop execution, immediate suspension of all AI processing operations and GPU kernel execution, multi-pass clearing executing within 15 ms total comprising Pass 1 random data (5 ms), Pass 2 zeros (3 ms), Pass 3 random data (5 ms), and verification (2 ms), audit event generation with timestamp, violation reason, wipe duration, and verification status, SecurityError thrown to calling code with descriptive message, return to safe state with all plaintext memory cleared and cryptographic verification completed, and prohibition of any further operations until new secure session established with fresh header validation.

15 . The method of claim 1 , further comprising integrity verification that computes SHA-256 hash of encrypted input data before decryption, records input hash in the audit chain with event type ‘INPUT_HASH’, computes SHA-256 hash of re-encrypted output data after AI processing, records output hash in the audit chain with event type ‘OUTPUT_HASH’, enables verification that outputs correspond to inputs without exposing plaintext data, detects any unauthorized modification of data during processing window, and generates integrity violation event if hash chain verification fails indicating tampering.

16 . The method of claim 1 , wherein verification parameters for XOR validation comprise bit-difference threshold set to configurable value defaulting to 40% of total buffer bits, sampling window size for statistical analysis of randomness, entropy measurement using Shannon entropy calculation on XOR result, correlation coefficient between Pass 1 and Pass 3 patterns confirming independence, and wherein all verification parameters including threshold value, sampling window, entropy score, and correlation coefficient are recorded in the audit chain for regulatory compliance and forensic analysis.

17 . The method of claim 1 , wherein the GPU buffer clearing within 100 ms timeout comprises allocation of clearing buffer with same dimensions as computational buffer, filling clearing buffer with cryptographically secure random data via crypto.getRandomValues( ), GPU queue write operation transferring clearing data to GPU buffer via device.queue.writeBuffer( ), synchronization via device.queue.onSubmittedWorkDone( ) ensuring clearing completion, timing verification confirming total duration from kernel completion to clearing completion is <100 ms, SecurityError generation with descriptive message if timeout exceeded, and audit event recording GPU buffer size, clearing duration, and verification status.

18 . The method of claim 1 , further comprising domain-specific optimizations wherein Healthcare mode configures T=800 ms with HIPAA audit format and Protected Health Information (PHI) data category tagging, Financial mode configures T=400 ms with PCI-DSS requirements and cardholder data handling restrictions, Legal mode configures T=1000 ms with attorney-client privilege protection and document classification, Communication mode configures T=100 ms with real-time constraints and minimal latency optimization, and Government mode configures T=500 ms with Federal Information Security Management Act (FISMA) compliance and classified data handling protocols, wherein each mode maintains all core security guarantees of steps (a) through (i) while optimizing for domain-specific regulatory requirements.

19 . The method of claim 1 , further comprising adaptive execution mode selection that detects WebGPU availability via navigator.gpu?.requestAdapter( ) with timeout, tests WebAssembly (WASM) SIMD support via instantiation of SIMD test module containing vector operations, measures baseline JavaScript performance via benchmark suite executing representative operations, selects execution mode achieving highest performance while maintaining all security guarantees, wherein WebGPU+SIMD+WASM mode achieves 60-80% total time reduction, WebGL+SIMD+WASM mode achieves 40-60% reduction, WASM+SIMD mode achieves 20-40% reduction, WASM scalar mode achieves 10-20% reduction, and JavaScript fallback achieves 5-15% reduction, and wherein mode selection is transparent to calling application and maintains identical security properties across all execution modes.

20 . The method of claim 1 , further comprising side-channel attack mitigation through constant-time operations using bitwise comparisons instead of conditional branches for all cryptographic operations and sensitive data comparisons, index masking preventing Spectre-style attacks via speculative execution by using bitwise AND operations to mask array indices, memory fences ensuring proper ordering of security-critical operations preventing compiler or CPU reordering, cache line alignment preventing cache timing attacks by ensuring sensitive data structures align to 64-byte boundaries, COOP/COEP headers enabling SharedArrayBuffer with high-precision timers for accurate performance measurements while maintaining isolation, and audit events recording timing anomalies when operation duration exceeds expected bounds by >10% indicating potential side-channel exploitation attempt.

21 . The method of claim 1 , wherein the security monitor intercepting access faults from guard pages implements fault detection via platform-specific mechanisms including segmentation fault signals on Portable Operating System Interface (POSIX) systems or structured exception handling on Windows, fault handler execution in isolated signal handler or exception filter preventing corruption of main execution context, audit event generation recording fault address, fault type, timestamp, and suspected cause, immediate emergency wipe sequence triggering upon fence violation, process termination after memory clearing preventing continued execution of potentially compromised code, and forensic data collection including stack trace and register state for security incident investigation.

22 . The method of claim 1 , wherein T=400 milliseconds for financial fraud detection operations processing transaction data with PCI-DSS compliance, T=600 milliseconds for legal document analysis with attorney-client privilege protection, T=250 milliseconds for content moderation with Children's Online Privacy Protection Act (COPPA) compliance for minor protection, and T=150 milliseconds for cybersecurity threat analysis with ultra-fast response requirements, wherein each domain-specific configuration maintains emergency wipe capability, XOR verification, HMAC audit chain, and all security guarantees of steps (a) through (i).

23 . The method of claim 1 , further comprising batch processing support that processes multiple encrypted data items sequentially within single secure session, maintains cumulative plaintext exposure time T_cumulative tracking sum of all decryption-to-re-encryption windows, enforces per-item plaintext window T_item≤1000 ms for each individual operation, enforces session-wide maximum T_cumulative≤10000 ms (10 seconds) preventing excessive aggregate exposure, generates audit chain entry for each batch item including item identifier and timing, executes complete memory clearing after final batch item processing, and generates batch summary audit event containing total items processed, cumulative exposure time, and per-item statistics for compliance verification.

24 . A system for secure client-side artificial intelligence processing with end-to-end encryption, comprising: a) a secure context validator configured to verify Hypertext Transfer Protocol Secure (HTTPS) protocol with Transport Layer Security (TLS) 1.3 or higher, Cross-Origin-Opener-Policy (COOP) header set to “same-origin”, Cross-Origin-Embedder-Policy (COEP) header set to “require-corp”, Strict-Transport-Security with max-age ≥31536000, and Origin Isolation policy, implementing a PASS/FAIL enforcement flow that terminates processing upon any validation failure and generates an audited REJECT event; b) a memory allocator implementing unmapped memory regions acting as guard pages that generate detectable access faults intercepted by a security monitor, 64-byte cache line alignment for all processing buffers, constant-time operations using bitwise comparisons to prevent timing attacks, and index masking with memory fences for Spectre mitigation; c) a WebAssembly execution environment comprising a dual-phase import control system with pattern-based whitelist and blacklist, a Security Monitor performing load-time parsing and instantiation-time verification, import table validation matching safe-operation patterns while rejecting disallowed patterns, and indirect call table restrictions with memory boundary enforcement; d) a bounded execution controller enforcing plaintext exposure time T≤1000 milliseconds with decryption timestamp recording via performance.now( ) with microsecond precision, monitoring loop executing every 100 ms via requestAnimationFrame, emergency wipe sequence completing within 15 ms upon timeout, and audit event generation for all violations; e) a Graphics Processing Unit (GPU) acceleration module when available, implementing a zero-copy tensor interface supporting Float16/Int8 formats, CPU to GPU transfer via ArrayBuffer.transfer( ) or equivalent zero-copy view/queue mapping mechanisms where supported without intermediate copies, mandatory plaintext clearing within 100 ms of kernel execution, SecurityError generation upon clearing timeout, and performance acceleration factors of Matrix operations 10-50×, Convolution 20-100×, Activation 5-20×; f) an audit chain generator creating tamper-evident logs using Hash-based Message Authentication Code (HMAC)-Secure Hash Algorithm (SHA)256 chaining with formula Hn=HMACk(Hn−1| event data ∥ nonce timestamp), genesis block initialization with SHA-256(masterKey+Date.now( )), 16-byte cryptographically secure nonce per event via crypto.getRandomValues( ), session key derivation via HMAC-based Key Derivation Function (HKDF)-Secure Hash Algorithm (SHA)256 with rotation every 86400000 ms (24 hours), and JavaScript Object Notation (JSON) and Comma-Separated Values (CSV) export formats with verification capability; g) a cryptographic processor implementing non-extractable key storage via Web Crypto Application Programming Interface (API), WebAuthn/Fast Identity Online (FIDO)2 binding for key access control, scheduled key rotation every 2592000000 ms (30 days), forward secrecy via HKDF-SHA256, and Post-Quantum Cryptography (PQC)-ready hybrid derivation with versioned algorithm flags; h) a verified memory wipe module implementing National Institute of Standards and Technology Special Publication (NIST SP) 800-88 Revision 1 with exactly 3 passes (configurable to n>3), XOR verification between first and third random passes with threshold validation, audit event generation with timing and verification status, and ArrayBuffer detachment with reference nulling; i) wherein the system collectively transforms the web browser from a standard execution environment into a secure Artificial Intelligence (AI) processing environment providing time-bounded plaintext exposure, verified memory clearing, and cryptographic audit capabilities not provided by a conventional browser architecture and security policies.

25 . The system of claim 24 , wherein the Security Monitor implements Phase 1 load-time validation parsing WebAssembly.Module.imports(module) to extract import descriptors, regex pattern matching against whitelist /{circumflex over ( )}(Math\.|Memory\.|Table\.|SIMD\.|WebGL\.|WebGPU\.|Performance\.now|Crypto.getRandomValues|Work er\.postMessage)/, regexpatternmatchingagainstblacklist/(DOM ‘|document’|window’|fetch|XMLHttpRequest|WebSocket|W/, immediate SecurityError on blacklist match with process termination, Phase 2 instantiation-time verification during WebAssembly.instantiate( ) validating actual import object, indirect call table validation ensuring no runtime import injection, memory bounds enforcement via WebAssembly.Memory constraints, Attestation Generator creating signed proof with Elliptic Curve Digital Signature Algorithm with a P-256 curve (ECDSA-P256), and Audit Chain Recording persisting attestation with timestamp and SHA-256 module hash.

26 . The system of claim 6 , further comprising a compliance certificate generator that captures processing session metadata including start time, end time, AI model identifier, data categories processed, and security events; binds certificate cryptographically to audit chain via hash reference creating tamper-evident linkage; generates regulatory-specific documentation for Health Insurance Portability and Accountability Act (HIPAA), Payment Card Industry Data Security Standard (PCI-DSS), General Data Protection Regulation (GDPR), California Consumer Privacy Act (CCPA), Family Educational Rights and Privacy Act (FERPA), and Financial Industry Regulatory Authority (FINRA) compliance frameworks; includes zero-knowledge proofs enabling third-party verification without exposing plaintext data; exports in JavaScript Object Notation (JSON), Extensible Markup Language (XML), or Portable Document Format (PDF) formats with ECDSA digital signature; and enables organizations to demonstrate compliance in certain deployment models without requiring Business Associate Agreements or compliance certifications from AI service providers.

27 . The system of claim 24 , further comprising a secure session manager that establishes session upon successful header validation in secure context validator, assigns unique session identifier via crypto.getRandomValues(new Uint8Array(32)) for tracking, initializes session-specific HMAC key via HKDF-SHA256(masterKey, session_id, “session-key”) for audit chain, tracks cumulative session duration and cumulative plaintext exposure time across multiple operations, enforces maximum session duration of 3600000 ms (1 hour) before requiring re-authentication, terminates session immediately upon any security violation with complete memory clearing sequence, generates session summary in audit chain containing all security events, plaintext exposure statistics, and violation records, and enables forensic analysis of processing sessions for compliance auditing and incident investigation.

28 . The system of claim 24 , further comprising failsafe mechanisms including a deadman switch that triggers memory clearing sequence if heartbeat signal from monitoring loop stops for >200 ms indicating potential crash or hang, a panic button accessible via keyboard shortcut (Ctrl+Shift+Esc) for immediate secure termination with emergency wipe, rate limiting preventing resource exhaustion attacks by limiting processing requests to maximum 10 per minute per origin, circuit breaker pattern for cascading failure prevention that opens after 3 consecutive security violations within 60 seconds, automatic rollback to safe state on any security violation with complete memory clearing and session termination, emergency contact notification via configurable webhook on critical security events, and tamper-evident seal on system configuration preventing unauthorized modification of security parameters.

29 . The system of claim 24 , further comprising multi-platform support enabling identical security guarantees across desktop browsers with full WebGPU support and hardware acceleration, mobile browsers with WebGL fallback and reduced memory footprint optimization, Electron applications with native integration and enhanced performance via Node.js addons, browser extensions with restricted permissions and Content Security Policy compliance, and Progressive Web Apps with offline capability and service worker integration for cached model execution, wherein all platforms implement identical security policies defined in components (a) through (i) with platform-specific performance optimizations that do not compromise security guarantees.

30 . A non-transitory computer-readable medium storing instructions that, when executed by a processor within a web browser, cause the web browser to perform operations comprising: a) enforcing security headers including Cross-Origin-Opener-Policy (COOP)=“same-origin”, Cross-Origin-Embedder-Policy (COEP)=“require-corp”, Hypertext Transfer Protocol Secure (HTTPS) with HTTP Strict Transport Security (HSTS), and Origin Isolation before any cryptographic operations; b) establishing memory-isolated execution environment with unmapped guard pages and cache-aligned buffers; c) restricting WebAssembly imports to computational operation patterns only while blocking Document Object Model (DOM), network, file system, and storage access patterns; d) decrypting data within bounded time window T≤1000 ms with automatic emergency wipe upon timeout; e) processing through Artificial Intelligence (AI) models achieving domain-specific latency targets without server communication; f) re-encrypting results before any persistence or network transmission; g) performing multi-pass verified memory clearing with XOR validation per National Institute of Standards and Technology Special Publication (NIST SP) 800-88; h) generating tamper-evident Hash-based Message Authentication Code (HMAC) audit chain with rotating session keys; i) utilizing non-extractable keys bound to Web Authn credentials; wherein the instructions transform the web browser into a secure Artificial Intelligence (AI) processing platform maintaining end-to-end encryption while enabling use of advanced AI models with regulated data in full regulatory compliance.