diff --git a/src/MatrixClientPeg.js b/src/MatrixClientPeg.js
index bebb254afc..ef0130ec15 100644
--- a/src/MatrixClientPeg.js
+++ b/src/MatrixClientPeg.js
@@ -220,6 +220,16 @@ class MatrixClientPeg {
             identityServer: new IdentityAuthClient(),
         };
 
+        if (SettingsStore.isFeatureEnabled("feature_cross_signing")) {
+            // TODO: Cross-signing keys are temporarily in memory only. A
+            // separate task in the cross-signing project will build from here.
+            const keys = [];
+            opts.cryptoCallbacks = {
+                getCrossSigningKey: k => keys[k],
+                saveCrossSigningKeys: newKeys => Object.assign(keys, newKeys),
+            };
+        }
+
         this.matrixClient = createMatrixClient(opts);
 
         // we're going to add eventlisteners for each matrix event tile, so the
diff --git a/src/i18n/strings/en_EN.json b/src/i18n/strings/en_EN.json
index 655c7030c4..c42a137800 100644
--- a/src/i18n/strings/en_EN.json
+++ b/src/i18n/strings/en_EN.json
@@ -343,6 +343,7 @@
     "Use the new, consistent UserInfo panel for Room Members and Group Members": "Use the new, consistent UserInfo panel for Room Members and Group Members",
     "Try out new ways to ignore people (experimental)": "Try out new ways to ignore people (experimental)",
     "Send verification requests in direct message": "Send verification requests in direct message",
+    "Enable cross-signing to verify per-user instead of per-device": "Enable cross-signing to verify per-user instead of per-device",
     "Use the new, faster, composer for writing messages": "Use the new, faster, composer for writing messages",
     "Enable Emoji suggestions while typing": "Enable Emoji suggestions while typing",
     "Use compact timeline layout": "Use compact timeline layout",
diff --git a/src/settings/Settings.js b/src/settings/Settings.js
index 973d389ba6..89bca043bd 100644
--- a/src/settings/Settings.js
+++ b/src/settings/Settings.js
@@ -23,7 +23,7 @@ import {
 } from "./controllers/NotificationControllers";
 import CustomStatusController from "./controllers/CustomStatusController";
 import ThemeController from './controllers/ThemeController';
-import LowBandwidthController from "./controllers/LowBandwidthController";
+import ReloadOnChangeController from "./controllers/ReloadOnChangeController";
 
 // These are just a bunch of helper arrays to avoid copy/pasting a bunch of times
 const LEVELS_ROOM_SETTINGS = ['device', 'room-device', 'room-account', 'account', 'config'];
@@ -146,6 +146,13 @@ export const SETTINGS = {
         supportedLevels: LEVELS_FEATURE,
         default: false,
     },
+    "feature_cross_signing": {
+        isFeature: true,
+        displayName: _td("Enable cross-signing to verify per-user instead of per-device"),
+        supportedLevels: LEVELS_FEATURE,
+        default: false,
+        controller: new ReloadOnChangeController(),
+    },
     "useCiderComposer": {
         displayName: _td("Use the new, faster, composer for writing messages"),
         supportedLevels: LEVELS_ACCOUNT_SETTINGS,
@@ -427,7 +434,7 @@ export const SETTINGS = {
         supportedLevels: LEVELS_DEVICE_ONLY_SETTINGS_WITH_CONFIG,
         displayName: _td('Low bandwidth mode'),
         default: false,
-        controller: new LowBandwidthController(),
+        controller: new ReloadOnChangeController(),
     },
     "fallbackICEServerAllowed": {
         supportedLevels: LEVELS_DEVICE_ONLY_SETTINGS,
diff --git a/src/settings/controllers/LowBandwidthController.js b/src/settings/controllers/ReloadOnChangeController.js
similarity index 91%
rename from src/settings/controllers/LowBandwidthController.js
rename to src/settings/controllers/ReloadOnChangeController.js
index c7796a425a..eadaee89ca 100644
--- a/src/settings/controllers/LowBandwidthController.js
+++ b/src/settings/controllers/ReloadOnChangeController.js
@@ -17,7 +17,7 @@ limitations under the License.
 import SettingController from "./SettingController";
 import PlatformPeg from "../../PlatformPeg";
 
-export default class LowBandwidthController extends SettingController {
+export default class ReloadOnChangeController extends SettingController {
     onChange(level, roomId, newValue) {
         PlatformPeg.get().reload();
     }