diff --git a/package-lock.json b/package-lock.json
index 4b0b5a2..a05fb32 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -11,6 +11,7 @@
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         "cbor-js": "0.1.0",
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         "pako": "2.1.0",
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@@ -18,9 +19,17 @@
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@@ -34,6 +43,217 @@
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       }
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+      "resolved": "https://registry.npmjs.org/@csstools/css-tokenizer/-/css-tokenizer-4.0.0.tgz",
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+      "dev": true,
+      "funding": [
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+          "url": "https://github.com/sponsors/csstools"
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+      "license": "MIT",
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@@ -476,6 +696,24 @@
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+      "resolved": "https://registry.npmjs.org/@exodus/bytes/-/bytes-1.15.0.tgz",
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+      "license": "MIT",
+      "engines": {
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@@ -752,6 +1007,16 @@
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@@ -905,6 +1170,20 @@
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+      "license": "MIT",
+      "dependencies": {
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+        "@csstools/css-syntax-patches-for-csstree": "^1.0.28",
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+        "lru-cache": "^11.2.6"
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+      "license": "BlueOak-1.0.0",
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+      "license": "MIT",
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@@ -927,6 +1264,13 @@
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@@ -1167,12 +1533,53 @@
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+      "license": "MIT",
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+      "version": "7.0.2",
+      "resolved": "https://registry.npmjs.org/http-proxy-agent/-/http-proxy-agent-7.0.2.tgz",
+      "integrity": "sha512-T1gkAiYYDWYx3V5Bmyu7HcfcvL7mUrTWiM6yOfa3PIphViJ/gFPbvidQ+veqSOHci/PxBcDabeUNCzpOODJZig==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "agent-base": "^7.1.0",
+        "debug": "^4.3.4"
+      },
+      "engines": {
+        "node": ">= 14"
+      }
+    },
+    "node_modules/https-proxy-agent": {
+      "version": "7.0.6",
+      "resolved": "https://registry.npmjs.org/https-proxy-agent/-/https-proxy-agent-7.0.6.tgz",
+      "integrity": "sha512-vK9P5/iUfdl95AI+JVyUuIcVtd4ofvtrOr3HNtM2yxC9bnMbEdp3x01OhQNnjb8IJYi38VlTE3mBXwcfvywuSw==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "agent-base": "^7.1.2",
+        "debug": "4"
+      },
+      "engines": {
+        "node": ">= 14"
+      }
+    },
     "node_modules/is-binary-path": {
       "version": "2.1.0",
       "resolved": "https://registry.npmjs.org/is-binary-path/-/is-binary-path-2.1.0.tgz",
@@ -1244,6 +1651,13 @@
         "node": ">=0.12.0"
       }
     },
+    "node_modules/is-potential-custom-element-name": {
+      "version": "1.0.1",
+      "resolved": "https://registry.npmjs.org/is-potential-custom-element-name/-/is-potential-custom-element-name-1.0.1.tgz",
+      "integrity": "sha512-bCYeRA2rVibKZd+s2625gGnGF/t7DSqDs4dP7CrLA1m7jKWz6pps0LpYLJN8Q64HtmPKJ1hrN3nzPNKFEKOUiQ==",
+      "dev": true,
+      "license": "MIT"
+    },
     "node_modules/isexe": {
       "version": "2.0.0",
       "resolved": "https://registry.npmjs.org/isexe/-/isexe-2.0.0.tgz",
@@ -1267,6 +1681,47 @@
         "@pkgjs/parseargs": "^0.11.0"
       }
     },
+    "node_modules/jsdom": {
+      "version": "28.1.0",
+      "resolved": "https://registry.npmjs.org/jsdom/-/jsdom-28.1.0.tgz",
+      "integrity": "sha512-0+MoQNYyr2rBHqO1xilltfDjV9G7ymYGlAUazgcDLQaUf8JDHbuGwsxN6U9qWaElZ4w1B2r7yEGIL3GdeW3Rug==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "@acemir/cssom": "^0.9.31",
+        "@asamuzakjp/dom-selector": "^6.8.1",
+        "@bramus/specificity": "^2.4.2",
+        "@exodus/bytes": "^1.11.0",
+        "cssstyle": "^6.0.1",
+        "data-urls": "^7.0.0",
+        "decimal.js": "^10.6.0",
+        "html-encoding-sniffer": "^6.0.0",
+        "http-proxy-agent": "^7.0.2",
+        "https-proxy-agent": "^7.0.6",
+        "is-potential-custom-element-name": "^1.0.1",
+        "parse5": "^8.0.0",
+        "saxes": "^6.0.0",
+        "symbol-tree": "^3.2.4",
+        "tough-cookie": "^6.0.0",
+        "undici": "^7.21.0",
+        "w3c-xmlserializer": "^5.0.0",
+        "webidl-conversions": "^8.0.1",
+        "whatwg-mimetype": "^5.0.0",
+        "whatwg-url": "^16.0.0",
+        "xml-name-validator": "^5.0.0"
+      },
+      "engines": {
+        "node": "^20.19.0 || ^22.12.0 || >=24.0.0"
+      },
+      "peerDependencies": {
+        "canvas": "^3.0.0"
+      },
+      "peerDependenciesMeta": {
+        "canvas": {
+          "optional": true
+        }
+      }
+    },
     "node_modules/lilconfig": {
       "version": "3.1.3",
       "resolved": "https://registry.npmjs.org/lilconfig/-/lilconfig-3.1.3.tgz",
@@ -1306,6 +1761,13 @@
       "dev": true,
       "license": "ISC"
     },
+    "node_modules/mdn-data": {
+      "version": "2.27.1",
+      "resolved": "https://registry.npmjs.org/mdn-data/-/mdn-data-2.27.1.tgz",
+      "integrity": "sha512-9Yubnt3e8A0OKwxYSXyhLymGW4sCufcLG6VdiDdUGVkPhpqLxlvP5vl1983gQjJl3tqbrM731mjaZaP68AgosQ==",
+      "dev": true,
+      "license": "CC0-1.0"
+    },
     "node_modules/merge2": {
       "version": "1.4.1",
       "resolved": "https://registry.npmjs.org/merge2/-/merge2-1.4.1.tgz",
@@ -1356,6 +1818,13 @@
         "node": ">=16 || 14 >=14.17"
       }
     },
+    "node_modules/ms": {
+      "version": "2.1.3",
+      "resolved": "https://registry.npmjs.org/ms/-/ms-2.1.3.tgz",
+      "integrity": "sha512-6FlzubTLZG3J2a/NVCAleEhjzq5oxgHyaCU9yYXvcLsvoVaHJq/s5xXI6/XXP6tz7R9xAOtHnSO/tXtF3WRTlA==",
+      "dev": true,
+      "license": "MIT"
+    },
     "node_modules/mz": {
       "version": "2.7.0",
       "resolved": "https://registry.npmjs.org/mz/-/mz-2.7.0.tgz",
@@ -1466,6 +1935,19 @@
       "integrity": "sha512-w+eufiZ1WuJYgPXbV/PO3NCMEc3xqylkKHzp8bxp1uW4qaSNQUkwmLLEc3kKsfz8lpV1F8Ht3U1Cm+9Srog2ug==",
       "license": "(MIT AND Zlib)"
     },
+    "node_modules/parse5": {
+      "version": "8.0.1",
+      "resolved": "https://registry.npmjs.org/parse5/-/parse5-8.0.1.tgz",
+      "integrity": "sha512-z1e/HMG90obSGeidlli3hj7cbocou0/wa5HacvI3ASx34PecNjNQeaHNo5WIZpWofN9kgkqV1q5YvXe3F0FoPw==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "entities": "^8.0.0"
+      },
+      "funding": {
+        "url": "https://github.com/inikulin/parse5?sponsor=1"
+      }
+    },
     "node_modules/path-exists": {
       "version": "4.0.0",
       "resolved": "https://registry.npmjs.org/path-exists/-/path-exists-4.0.0.tgz",
@@ -1708,6 +2190,16 @@
       "dev": true,
       "license": "MIT"
     },
+    "node_modules/punycode": {
+      "version": "2.3.1",
+      "resolved": "https://registry.npmjs.org/punycode/-/punycode-2.3.1.tgz",
+      "integrity": "sha512-vYt7UD1U9Wg6138shLtLOvdAu+8DsC/ilFtEVHcH+wydcSpNE20AfSOduf6MkRFahL5FY7X1oU7nKVZFtfq8Fg==",
+      "dev": true,
+      "license": "MIT",
+      "engines": {
+        "node": ">=6"
+      }
+    },
     "node_modules/qr-scanner": {
       "version": "1.4.2",
       "resolved": "https://registry.npmjs.org/qr-scanner/-/qr-scanner-1.4.2.tgz",
@@ -1787,6 +2279,16 @@
         "node": ">=0.10.0"
       }
     },
+    "node_modules/require-from-string": {
+      "version": "2.0.2",
+      "resolved": "https://registry.npmjs.org/require-from-string/-/require-from-string-2.0.2.tgz",
+      "integrity": "sha512-Xf0nWe6RseziFMu+Ap9biiUbmplq6S9/p+7w7YXP/JBHhrUDDUhwa+vANyubuqfZWTveU//DYVGsDG7RKL/vEw==",
+      "dev": true,
+      "license": "MIT",
+      "engines": {
+        "node": ">=0.10.0"
+      }
+    },
     "node_modules/require-main-filename": {
       "version": "2.0.0",
       "resolved": "https://registry.npmjs.org/require-main-filename/-/require-main-filename-2.0.0.tgz",
@@ -1849,6 +2351,19 @@
         "queue-microtask": "^1.2.2"
       }
     },
+    "node_modules/saxes": {
+      "version": "6.0.0",
+      "resolved": "https://registry.npmjs.org/saxes/-/saxes-6.0.0.tgz",
+      "integrity": "sha512-xAg7SOnEhrm5zI3puOOKyy1OMcMlIJZYNJY7xLBwSze0UjhPLnWfj2GF2EpT0jmzaJKIWKHLsaSSajf35bcYnA==",
+      "dev": true,
+      "license": "ISC",
+      "dependencies": {
+        "xmlchars": "^2.2.0"
+      },
+      "engines": {
+        "node": ">=v12.22.7"
+      }
+    },
     "node_modules/set-blocking": {
       "version": "2.0.0",
       "resolved": "https://registry.npmjs.org/set-blocking/-/set-blocking-2.0.0.tgz",
@@ -1993,6 +2508,13 @@
         "url": "https://github.com/sponsors/ljharb"
       }
     },
+    "node_modules/symbol-tree": {
+      "version": "3.2.4",
+      "resolved": "https://registry.npmjs.org/symbol-tree/-/symbol-tree-3.2.4.tgz",
+      "integrity": "sha512-9QNk5KwDF+Bvz+PyObkmSYjI5ksVUYtjW7AU22r2NKcfLJcXp96hkDWU3+XndOsUb+AQ9QhfzfCT2O+CNWT5Tw==",
+      "dev": true,
+      "license": "MIT"
+    },
     "node_modules/tailwindcss": {
       "version": "3.4.17",
       "resolved": "https://registry.npmjs.org/tailwindcss/-/tailwindcss-3.4.17.tgz",
@@ -2064,6 +2586,26 @@
         "node": ">=0.8"
       }
     },
+    "node_modules/tldts": {
+      "version": "7.0.30",
+      "resolved": "https://registry.npmjs.org/tldts/-/tldts-7.0.30.tgz",
+      "integrity": "sha512-ELrFxuqsDdHUwoh0XxDbxuLD3Wnz49Z57IFvTtvWy1hJdcMZjXLIuonjilCiWHlT2GbE4Wlv1wKVTzDFnXH1aw==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "tldts-core": "^7.0.30"
+      },
+      "bin": {
+        "tldts": "bin/cli.js"
+      }
+    },
+    "node_modules/tldts-core": {
+      "version": "7.0.30",
+      "resolved": "https://registry.npmjs.org/tldts-core/-/tldts-core-7.0.30.tgz",
+      "integrity": "sha512-uiHN8PIB1VmWyS98eZYja4xzlYqeFZVjb4OuYlJQnZAuJhMw4PbKQOKgHKhBdJR3FE/t5mUQ1Kd80++B+qhD1Q==",
+      "dev": true,
+      "license": "MIT"
+    },
     "node_modules/to-regex-range": {
       "version": "5.0.1",
       "resolved": "https://registry.npmjs.org/to-regex-range/-/to-regex-range-5.0.1.tgz",
@@ -2077,6 +2619,32 @@
         "node": ">=8.0"
       }
     },
+    "node_modules/tough-cookie": {
+      "version": "6.0.1",
+      "resolved": "https://registry.npmjs.org/tough-cookie/-/tough-cookie-6.0.1.tgz",
+      "integrity": "sha512-LktZQb3IeoUWB9lqR5EWTHgW/VTITCXg4D21M+lvybRVdylLrRMnqaIONLVb5mav8vM19m44HIcGq4qASeu2Qw==",
+      "dev": true,
+      "license": "BSD-3-Clause",
+      "dependencies": {
+        "tldts": "^7.0.5"
+      },
+      "engines": {
+        "node": ">=16"
+      }
+    },
+    "node_modules/tr46": {
+      "version": "6.0.0",
+      "resolved": "https://registry.npmjs.org/tr46/-/tr46-6.0.0.tgz",
+      "integrity": "sha512-bLVMLPtstlZ4iMQHpFHTR7GAGj2jxi8Dg0s2h2MafAE4uSWF98FC/3MomU51iQAMf8/qDUbKWf5GxuvvVcXEhw==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "punycode": "^2.3.1"
+      },
+      "engines": {
+        "node": ">=20"
+      }
+    },
     "node_modules/ts-interface-checker": {
       "version": "0.1.13",
       "resolved": "https://registry.npmjs.org/ts-interface-checker/-/ts-interface-checker-0.1.13.tgz",
@@ -2084,6 +2652,16 @@
       "dev": true,
       "license": "Apache-2.0"
     },
+    "node_modules/undici": {
+      "version": "7.25.0",
+      "resolved": "https://registry.npmjs.org/undici/-/undici-7.25.0.tgz",
+      "integrity": "sha512-xXnp4kTyor2Zq+J1FfPI6Eq3ew5h6Vl0F/8d9XU5zZQf1tX9s2Su1/3PiMmUANFULpmksxkClamIZcaUqryHsQ==",
+      "dev": true,
+      "license": "MIT",
+      "engines": {
+        "node": ">=20.18.1"
+      }
+    },
     "node_modules/util-deprecate": {
       "version": "1.0.2",
       "resolved": "https://registry.npmjs.org/util-deprecate/-/util-deprecate-1.0.2.tgz",
@@ -2091,6 +2669,54 @@
       "dev": true,
       "license": "MIT"
     },
+    "node_modules/w3c-xmlserializer": {
+      "version": "5.0.0",
+      "resolved": "https://registry.npmjs.org/w3c-xmlserializer/-/w3c-xmlserializer-5.0.0.tgz",
+      "integrity": "sha512-o8qghlI8NZHU1lLPrpi2+Uq7abh4GGPpYANlalzWxyWteJOCsr/P+oPBA49TOLu5FTZO4d3F9MnWJfiMo4BkmA==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "xml-name-validator": "^5.0.0"
+      },
+      "engines": {
+        "node": ">=18"
+      }
+    },
+    "node_modules/webidl-conversions": {
+      "version": "8.0.1",
+      "resolved": "https://registry.npmjs.org/webidl-conversions/-/webidl-conversions-8.0.1.tgz",
+      "integrity": "sha512-BMhLD/Sw+GbJC21C/UgyaZX41nPt8bUTg+jWyDeg7e7YN4xOM05YPSIXceACnXVtqyEw/LMClUQMtMZ+PGGpqQ==",
+      "dev": true,
+      "license": "BSD-2-Clause",
+      "engines": {
+        "node": ">=20"
+      }
+    },
+    "node_modules/whatwg-mimetype": {
+      "version": "5.0.0",
+      "resolved": "https://registry.npmjs.org/whatwg-mimetype/-/whatwg-mimetype-5.0.0.tgz",
+      "integrity": "sha512-sXcNcHOC51uPGF0P/D4NVtrkjSU2fNsm9iog4ZvZJsL3rjoDAzXZhkm2MWt1y+PUdggKAYVoMAIYcs78wJ51Cw==",
+      "dev": true,
+      "license": "MIT",
+      "engines": {
+        "node": ">=20"
+      }
+    },
+    "node_modules/whatwg-url": {
+      "version": "16.0.1",
+      "resolved": "https://registry.npmjs.org/whatwg-url/-/whatwg-url-16.0.1.tgz",
+      "integrity": "sha512-1to4zXBxmXHV3IiSSEInrreIlu02vUOvrhxJJH5vcxYTBDAx51cqZiKdyTxlecdKNSjj8EcxGBxNf6Vg+945gw==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "@exodus/bytes": "^1.11.0",
+        "tr46": "^6.0.0",
+        "webidl-conversions": "^8.0.1"
+      },
+      "engines": {
+        "node": "^20.19.0 || ^22.12.0 || >=24.0.0"
+      }
+    },
     "node_modules/which": {
       "version": "2.0.2",
       "resolved": "https://registry.npmjs.org/which/-/which-2.0.2.tgz",
@@ -2146,6 +2772,23 @@
         "url": "https://github.com/chalk/wrap-ansi?sponsor=1"
       }
     },
+    "node_modules/xml-name-validator": {
+      "version": "5.0.0",
+      "resolved": "https://registry.npmjs.org/xml-name-validator/-/xml-name-validator-5.0.0.tgz",
+      "integrity": "sha512-EvGK8EJ3DhaHfbRlETOWAS5pO9MZITeauHKJyb8wyajUfQUenkIg2MvLDTZ4T/TgIcm3HU0TFBgWWboAZ30UHg==",
+      "dev": true,
+      "license": "Apache-2.0",
+      "engines": {
+        "node": ">=18"
+      }
+    },
+    "node_modules/xmlchars": {
+      "version": "2.2.0",
+      "resolved": "https://registry.npmjs.org/xmlchars/-/xmlchars-2.2.0.tgz",
+      "integrity": "sha512-JZnDKK8B0RCDw84FNdDAIpZK+JuJw+s7Lz8nksI7SIuU3UXJJslUthsi+uWBUYOwPFwW7W7PRLRfUKpxjtjFCw==",
+      "dev": true,
+      "license": "MIT"
+    },
     "node_modules/y18n": {
       "version": "4.0.3",
       "resolved": "https://registry.npmjs.org/y18n/-/y18n-4.0.3.tgz",
diff --git a/package.json b/package.json
index e51122c..f91e7a7 100644
--- a/package.json
+++ b/package.json
@@ -25,11 +25,13 @@
   "license": "MIT",
   "devDependencies": {
     "esbuild": "0.25.9",
+    "jsdom": "^28.1.0",
     "tailwindcss": "3.4.17"
   },
   "dependencies": {
     "base64-js": "1.5.1",
     "cbor-js": "0.1.0",
+    "dompurify": "^3.4.4",
     "html5-qrcode": "2.3.8",
     "pako": "2.1.0",
     "qr-scanner": "1.4.2",
diff --git a/src/crypto/EnhancedSecureCryptoUtils.js b/src/crypto/EnhancedSecureCryptoUtils.js
index e837d4b..0c9aa9e 100644
--- a/src/crypto/EnhancedSecureCryptoUtils.js
+++ b/src/crypto/EnhancedSecureCryptoUtils.js
@@ -1,6 +1,9 @@
+import createDOMPurify from 'dompurify';
+
 class EnhancedSecureCryptoUtils {
 
     static _keyMetadata = new WeakMap();
+    static _messageSanitizer = null;
     
     // Initialize secure logging system after class definition
 
@@ -2420,86 +2423,43 @@ class EnhancedSecureCryptoUtils {
         }
     }
 
-    // Enhanced input sanitization with iterative processing to handle edge cases
+    static _getMessageSanitizer() {
+        if (EnhancedSecureCryptoUtils._messageSanitizer) {
+            return EnhancedSecureCryptoUtils._messageSanitizer;
+        }
+
+        if (typeof window === 'undefined' || !window?.document) {
+            throw new Error('DOMPurify requires a browser-like window for message sanitization');
+        }
+
+        EnhancedSecureCryptoUtils._messageSanitizer = createDOMPurify(window);
+        return EnhancedSecureCryptoUtils._messageSanitizer;
+    }
+
+    // Centralized chat-message sanitization. Messages are rendered as plain text,
+    // so the safest compatible output is text-only content with no markup surface.
     static sanitizeMessage(message) {
         if (typeof message !== 'string') {
             throw new Error('Message must be a string');
         }
-        
-        // Helper function to apply replacement until stable
-        function replaceUntilStable(str, pattern, replacement = '') {
-            let previous;
-            do {
-                previous = str;
-                str = str.replace(pattern, replacement);
-            } while (str !== previous);
-            return str;
-        }
-        
-        // Define all dangerous patterns that need to be removed
-        const dangerousPatterns = [
-            // Script tags with various formats
-            /<script\b[^>]*>[\s\S]*?<\/script\s*>/gi,
-            /<script\b[^>]*>[\s\S]*?<\/script\s+[^>]*>/gi,
-            /<script\b[^>]*>[\s\S]*$/gi,
-            // Other dangerous tags
-            /<iframe\b[^>]*>[\s\S]*?<\/iframe\s*>/gi,
-            /<object\b[^>]*>[\s\S]*?<\/object\s*>/gi,
-            /<embed\b[^>]*>/gi,
-            /<applet\b[^>]*>[\s\S]*?<\/applet\s*>/gi,
-            /<style\b[^>]*>[\s\S]*?<\/style\s*>/gi,
-            // Dangerous protocols
-            /javascript\s*:/gi,
-            /data\s*:/gi,
-            /vbscript\s*:/gi,
-            // Event handlers
-            /on\w+\s*=/gi,
-            // HTML comments
-            /<!--[\s\S]*?-->/g,
-            // Link and meta tags with javascript
-            /<link\b[^>]*javascript[^>]*>/gi,
-            /<meta\b[^>]*javascript[^>]*>/gi,
-            // Any remaining script-like content
-            /<[^>]*script[^>]*>/gi,
-            /<[^>]*on\w+\s*=[^>]*>/gi
-        ];
-        
-        // Iterative sanitization to handle edge cases
-        let sanitized = message;
-        let previousLength;
-        let iterations = 0;
-        const maxIterations = 10; // Prevent infinite loops
-        
-        do {
-            previousLength = sanitized.length;
-            
-            // Apply all dangerous patterns with stable replacement
-            for (const pattern of dangerousPatterns) {
-                sanitized = replaceUntilStable(sanitized, pattern);
+
+        const sanitized = EnhancedSecureCryptoUtils._getMessageSanitizer().sanitize(message, {
+            ALLOWED_TAGS: [],
+            ALLOWED_ATTR: [],
+            ALLOW_UNKNOWN_PROTOCOLS: false,
+            FORBID_TAGS: ['script', 'style', 'svg', 'math', 'template'],
+            FORBID_ATTR: ['style'],
+            KEEP_CONTENT: true,
+            RETURN_TRUSTED_TYPE: false,
+            USE_PROFILES: {
+                html: false,
+                svg: false,
+                svgFilters: false,
+                mathMl: false
             }
-            
-            // Additional cleanup for edge cases - each applied until stable
-            sanitized = replaceUntilStable(sanitized, /<[^>]*>/g);
-            sanitized = replaceUntilStable(sanitized, /^\w+:/gi);
-            sanitized = replaceUntilStable(sanitized, /\bon\w+\s*=\s*["'][^"']*["']/gi);
-            sanitized = replaceUntilStable(sanitized, /\bon\w+\s*=\s*[^>\s]+/gi);
-            
-            // Single character removal is inherently safe
-            sanitized = sanitized.replace(/[<>]/g, '').trim();
-            
-            iterations++;
-        } while (sanitized.length !== previousLength && iterations < maxIterations);
-        
-        // Final security pass with stable replacements
-        sanitized = replaceUntilStable(sanitized, /<[^>]*>/g);
-        sanitized = replaceUntilStable(sanitized, /^\w+:/gi);
-        sanitized = replaceUntilStable(sanitized, /\bon\w+\s*=\s*["'][^"']*["']/gi);
-        sanitized = replaceUntilStable(sanitized, /\bon\w+\s*=\s*[^>\s]+/gi);
-        
-        // Final single character cleanup
-        sanitized = sanitized.replace(/[<>]/g, '').trim();
-        
-        return sanitized.substring(0, 2000); // Limit length
+        });
+
+        return String(sanitized).trim().substring(0, 2000);
     }
 
     // Generate cryptographically secure salt (64 bytes for enhanced security)
@@ -2668,4 +2628,4 @@ class EnhancedSecureCryptoUtils {
     }
 }
 
-export { EnhancedSecureCryptoUtils };
\ No newline at end of file
+export { EnhancedSecureCryptoUtils };
diff --git a/tests/incoming-message-sanitization.test.mjs b/tests/incoming-message-sanitization.test.mjs
index c9a9790..49dee3a 100644
--- a/tests/incoming-message-sanitization.test.mjs
+++ b/tests/incoming-message-sanitization.test.mjs
@@ -1,14 +1,13 @@
 import assert from 'node:assert/strict';
+import { JSDOM } from 'jsdom';
 
-globalThis.window = {
-    DEBUG_MODE: true,
-    DEVELOPMENT_MODE: true,
-    webpackHotUpdate: {},
-    location: {
-        hostname: 'localhost',
-        search: '?debug'
-    }
-};
+const { window } = new JSDOM('<!doctype html><html><body></body></html>', {
+    url: 'http://localhost/?debug'
+});
+window.DEBUG_MODE = true;
+window.DEVELOPMENT_MODE = true;
+window.webpackHotUpdate = {};
+globalThis.window = window;
 
 const { EnhancedSecureCryptoUtils } = await import('../src/crypto/EnhancedSecureCryptoUtils.js');
 window.EnhancedSecureCryptoUtils = EnhancedSecureCryptoUtils;
@@ -33,18 +32,38 @@ function createManager() {
     assert.deepEqual(manager.delivered[0], { message: 'hello secure world', type: 'received' });
 }
 
-// XSS-like and HTML payloads are sanitized before UI delivery.
+// Script payloads are removed while harmless visible text survives.
 {
     const manager = createManager();
     EnhancedSecureWebRTCManager.prototype.deliverMessageToUI.call(manager, '<script>alert(1)</script>Hello <b>peer</b>', 'received');
     assert.deepEqual(manager.delivered[0], { message: 'Hello peer', type: 'received' });
 }
 
-// Event-handler and protocol strings are removed before reaching React state.
+// Dangerous protocols in markup and event handlers never reach React state.
 {
     const manager = createManager();
-    EnhancedSecureWebRTCManager.prototype.deliverMessageToUI.call(manager, '<img src=x onerror=alert(1)> javascript:alert(1)', 'received');
-    assert.deepEqual(manager.delivered[0], { message: 'alert(1)', type: 'received' });
+    EnhancedSecureWebRTCManager.prototype.deliverMessageToUI.call(manager, '<a href="javascript:alert(1)">click</a><details ontoggle="alert(1)">open</details>', 'received');
+    assert.deepEqual(manager.delivered[0], { message: 'clickopen', type: 'received' });
+}
+
+// SVG payloads and malformed HTML do not create executable remnants.
+{
+    const manager = createManager();
+    EnhancedSecureWebRTCManager.prototype.deliverMessageToUI.call(manager, '<svg><script>alert(1)</script><a xlink:href="javascript:alert(2)">x</a></svg>', 'received');
+    assert.deepEqual(manager.delivered[0], { message: '', type: 'received' });
+
+    const malformedManager = createManager();
+    EnhancedSecureWebRTCManager.prototype.deliverMessageToUI.call(malformedManager, '<div><b>Hello<script>alert(1)', 'received');
+    assert.deepEqual(malformedManager.delivered[0], { message: 'Hello', type: 'received' });
+}
+
+// Plain text and Unicode text stay plain and intact.
+{
+    const manager = createManager();
+    EnhancedSecureWebRTCManager.prototype.deliverMessageToUI.call(manager, 'javascript: is harmless as plain text', 'received');
+    EnhancedSecureWebRTCManager.prototype.deliverMessageToUI.call(manager, 'Привет 👋 こんにちは', 'received');
+    assert.deepEqual(manager.delivered[0], { message: 'javascript: is harmless as plain text', type: 'received' });
+    assert.deepEqual(manager.delivered[1], { message: 'Привет 👋 こんにちは', type: 'received' });
 }
 
 // Outgoing/system messages are not altered by the incoming-message gate.