diff --git a/package-lock.json b/package-lock.json
index 27a7962..e46ad78 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -56,9 +56,9 @@
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+      "version": "4.4.2",
+      "resolved": "https://registry.npmjs.org/@openzeppelin/contracts/-/contracts-4.4.2.tgz",
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+      "resolved": "https://registry.npmjs.org/@types/pbkdf2/-/pbkdf2-3.1.0.tgz",
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+      "dev": true,
+      "requires": {
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+      "resolved": "https://registry.npmjs.org/@types/secp256k1/-/secp256k1-4.0.3.tgz",
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@@ -448,6 +466,15 @@
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+      "resolved": "https://registry.npmjs.org/base-x/-/base-x-3.0.9.tgz",
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@@ -479,6 +506,12 @@
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+      "resolved": "https://registry.npmjs.org/blakejs/-/blakejs-1.1.1.tgz",
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@@ -666,6 +699,26 @@
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+      "resolved": "https://registry.npmjs.org/bs58/-/bs58-4.0.1.tgz",
+      "integrity": "sha1-vhYedsNU9veIrkBx9j806MTwpCo=",
+      "dev": true,
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+      "resolved": "https://registry.npmjs.org/bs58check/-/bs58check-2.1.2.tgz",
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@@ -2108,6 +2161,37 @@
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+        "create-hmac": "^1.1.7",
+        "hash.js": "^1.1.7",
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+        "randombytes": "^2.1.0",
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+        "setimmediate": "^1.0.5"
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@@ -3459,7 +3543,8 @@
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@@ -3959,12 +4060,14 @@
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+      "integrity": "sha512-iWjXZvmboq0ja1pUGULQBexmxq8CV4xBhX7VDOTbL7ZR4FOowwY/VOtRxBN/yKxmdGoIp4j5ysNT4u3S2pDQ3Q==",
+      "dev": true
+    },
     "nopt": {
       "version": "3.0.6",
       "resolved": "https://registry.npmjs.org/nopt/-/nopt-3.0.6.tgz",
@@ -21051,6 +21345,40 @@
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       "dev": true
     },
+    "secp256k1": {
+      "version": "4.0.3",
+      "resolved": "https://registry.npmjs.org/secp256k1/-/secp256k1-4.0.3.tgz",
+      "integrity": "sha512-NLZVf+ROMxwtEj3Xa562qgv2BK5e2WNmXPiOdVIPLgs6lyTzMvBq0aWTYMI5XCP9jZMVKOcqZLw/Wc4vDkuxhA==",
+      "dev": true,
+      "requires": {
+        "elliptic": "^6.5.4",
+        "node-addon-api": "^2.0.0",
+        "node-gyp-build": "^4.2.0"
+      },
+      "dependencies": {
+        "bn.js": {
+          "version": "4.12.0",
+          "resolved": "https://registry.npmjs.org/bn.js/-/bn.js-4.12.0.tgz",
+          "integrity": "sha512-c98Bf3tPniI+scsdk237ku1Dc3ujXQTSgyiPUDEOe7tRkhrqridvh8klBv0HCEso1OLOYcHuCv/cS6DNxKH+ZA==",
+          "dev": true
+        },
+        "elliptic": {
+          "version": "6.5.4",
+          "resolved": "https://registry.npmjs.org/elliptic/-/elliptic-6.5.4.tgz",
+          "integrity": "sha512-iLhC6ULemrljPZb+QutR5TQGB+pdW6KGD5RSegS+8sorOZT+rdQFbsQFJgvN3eRqNALqJer4oQ16YvJHlU8hzQ==",
+          "dev": true,
+          "requires": {
+            "bn.js": "^4.11.9",
+            "brorand": "^1.1.0",
+            "hash.js": "^1.0.0",
+            "hmac-drbg": "^1.0.1",
+            "inherits": "^2.0.4",
+            "minimalistic-assert": "^1.0.1",
+            "minimalistic-crypto-utils": "^1.0.1"
+          }
+        }
+      }
+    },
     "seek-bzip": {
       "version": "1.0.5",
       "resolved": "https://registry.npmjs.org/seek-bzip/-/seek-bzip-1.0.5.tgz",
@@ -22919,6 +23247,35 @@
         "underscore": "1.9.1",
         "web3-core-helpers": "1.2.1",
         "websocket": "github:web3-js/WebSocket-Node#905deb4812572b344f5801f8c9ce8bb02799d82e"
+      },
+      "dependencies": {
+        "debug": {
+          "version": "2.6.9",
+          "resolved": "https://registry.npmjs.org/debug/-/debug-2.6.9.tgz",
+          "integrity": "sha512-bC7ElrdJaJnPbAP+1EotYvqZsb3ecl5wi6Bfi6BJTUcNowp6cvspg0jXznRTKDjm/E7AdgFBVeAPVMNcKGsHMA==",
+          "dev": true,
+          "requires": {
+            "ms": "2.0.0"
+          }
+        },
+        "ms": {
+          "version": "2.0.0",
+          "resolved": "https://registry.npmjs.org/ms/-/ms-2.0.0.tgz",
+          "integrity": "sha1-VgiurfwAvmwpAd9fmGF4jeDVl8g=",
+          "dev": true
+        },
+        "websocket": {
+          "version": "github:web3-js/WebSocket-Node#905deb4812572b344f5801f8c9ce8bb02799d82e",
+          "from": "github:web3-js/WebSocket-Node#polyfill/globalThis",
+          "dev": true,
+          "requires": {
+            "debug": "^2.2.0",
+            "es5-ext": "^0.10.50",
+            "nan": "^2.14.0",
+            "typedarray-to-buffer": "^3.1.5",
+            "yaeti": "^0.0.6"
+          }
+        }
       }
     },
     "web3-shh": {
@@ -22961,35 +23318,6 @@
         }
       }
     },
-    "websocket": {
-      "version": "github:web3-js/WebSocket-Node#905deb4812572b344f5801f8c9ce8bb02799d82e",
-      "from": "github:web3-js/WebSocket-Node#polyfill/globalThis",
-      "dev": true,
-      "requires": {
-        "debug": "^2.2.0",
-        "es5-ext": "^0.10.50",
-        "nan": "^2.14.0",
-        "typedarray-to-buffer": "^3.1.5",
-        "yaeti": "^0.0.6"
-      },
-      "dependencies": {
-        "debug": {
-          "version": "2.6.9",
-          "resolved": "https://registry.npmjs.org/debug/-/debug-2.6.9.tgz",
-          "integrity": "sha512-bC7ElrdJaJnPbAP+1EotYvqZsb3ecl5wi6Bfi6BJTUcNowp6cvspg0jXznRTKDjm/E7AdgFBVeAPVMNcKGsHMA==",
-          "dev": true,
-          "requires": {
-            "ms": "2.0.0"
-          }
-        },
-        "ms": {
-          "version": "2.0.0",
-          "resolved": "https://registry.npmjs.org/ms/-/ms-2.0.0.tgz",
-          "integrity": "sha1-VgiurfwAvmwpAd9fmGF4jeDVl8g=",
-          "dev": true
-        }
-      }
-    },
     "which": {
       "version": "1.3.1",
       "resolved": "https://registry.npmjs.org/which/-/which-1.3.1.tgz",
diff --git a/package.json b/package.json
index 02a2189..f39e6b4 100644
--- a/package.json
+++ b/package.json
@@ -12,7 +12,7 @@
     "ethlint": "1.2.5",
     "ganache-core": "2.8.0",
     "lodash": "^4.17.15",
-    "@openzeppelin/contracts": "2.3.0",
+    "@openzeppelin/contracts": "4.4.2",
     "solidity-coverage": "^0.6.7",
     "truffle": "5.0.42",
     "web3": "1.2.1"