diff --git a/lib/permissions/minimally-encoded-thread-permissions.js b/lib/permissions/minimally-encoded-thread-permissions.js
--- a/lib/permissions/minimally-encoded-thread-permissions.js
+++ b/lib/permissions/minimally-encoded-thread-permissions.js
@@ -127,10 +127,39 @@
   return bitmask.toString(16);
 };
 
+// TODO (atul): Update flow to `194.0.0` for bigint support
+// $FlowIssue bigint-unsupported
+const inversePermissionVariantBit: Map<bigint, string> = new Map(
+  Object.entries(permissionVariantBit).map(([key, value]) => [value, key]),
+);
+
+const bitmaskHexToRolePermissions = (
+  bitmaskHex: string,
+): ThreadRolePermissionsBlob => {
+  const bitmask = BigInt(`0x${bitmaskHex}`);
+  const threadRolePermissions = {};
+
+  Object.keys(minimallyEncodedThreadPermissions).forEach((permission, idx) => {
+    // Extract 12-bit segment for this permission
+    const shiftAmount = BigInt(idx) * BigInt(12);
+    // `& BigInt('0xfff')` masks all but lowest 12 bits
+    const permissionBitmask = (bitmask >> shiftAmount) & BigInt('0xfff');
+
+    inversePermissionVariantBit.forEach((value, key) => {
+      if ((permissionBitmask & key) === key) {
+        threadRolePermissions[`${value}${permission}`] = true;
+      }
+    });
+  });
+
+  return threadRolePermissions;
+};
+
 export {
   minimallyEncodedThreadPermissions,
   permissionsToBitmaskHex,
   hasPermission,
   rolePermissionToBitmask,
   rolePermissionsToBitmaskHex,
+  bitmaskHexToRolePermissions,
 };
diff --git a/lib/permissions/minimally-encoded-thread-permissions.test.js b/lib/permissions/minimally-encoded-thread-permissions.test.js
--- a/lib/permissions/minimally-encoded-thread-permissions.test.js
+++ b/lib/permissions/minimally-encoded-thread-permissions.test.js
@@ -1,6 +1,7 @@
 // @flow
 
 import {
+  bitmaskHexToRolePermissions,
   hasPermission,
   permissionsToBitmaskHex,
   rolePermissionsToBitmaskHex,
@@ -230,5 +231,19 @@
     expect(bitmaskB).toBe(
       '1001001001000001001001b24001001000001001001001001c7dc7d',
     );
+
+    expect(
+      bitmaskHexToRolePermissions(
+        '1001001001000001001001b24001001000001001001001001c7dc7d',
+      ),
+    ).toStrictEqual(permissionsB);
+
+    expect(
+      rolePermissionsToBitmaskHex(
+        bitmaskHexToRolePermissions(
+          '1001001001000001001001b24001001000001001001001001c7dc7d',
+        ),
+      ),
+    ).toStrictEqual('1001001001000001001001b24001001000001001001001001c7dc7d');
   });
 });