diff --git a/src/analytics/PosthogAnalytics.ts b/src/analytics/PosthogAnalytics.ts
index 05979a89..ca0df15f 100644
--- a/src/analytics/PosthogAnalytics.ts
+++ b/src/analytics/PosthogAnalytics.ts
@@ -73,6 +73,7 @@ interface PlatformProperties {
   appVersion: string;
   matrixBackend: "embedded" | "jssdk";
   callBackend: "livekit" | "full-mesh";
+  cryptoVersion?: string;
 }
 
 interface PosthogSettings {
@@ -193,6 +194,9 @@ export class PosthogAnalytics {
       appVersion,
       matrixBackend: widget ? "embedded" : "jssdk",
       callBackend: "livekit",
+      cryptoVersion: widget
+        ? undefined
+        : window.matrixclient.getCrypto()?.getVersion(),
     };
   }
 
diff --git a/src/analytics/PosthogEvents.ts b/src/analytics/PosthogEvents.ts
index 778392ba..1776b4ed 100644
--- a/src/analytics/PosthogEvents.ts
+++ b/src/analytics/PosthogEvents.ts
@@ -16,19 +16,40 @@ limitations under the License.
 
 import { DisconnectReason } from "livekit-client";
 import { logger } from "matrix-js-sdk/src/logger";
+import { MatrixRTCSession } from "matrix-js-sdk/src/matrixrtc";
 
 import {
   IPosthogEvent,
   PosthogAnalytics,
   RegistrationType,
 } from "./PosthogAnalytics";
+import { E2eeType } from "../e2ee/e2eeType";
 
+type EncryptionScheme = "none" | "shared" | "per_sender";
+
+function mapE2eeType(type: E2eeType): EncryptionScheme {
+  switch (type) {
+    case E2eeType.NONE:
+      return "none";
+    case E2eeType.SHARED_KEY:
+      return "shared";
+    case E2eeType.PER_PARTICIPANT:
+      return "per_sender";
+  }
+}
 interface CallEnded extends IPosthogEvent {
   eventName: "CallEnded";
   callId: string;
   callParticipantsOnLeave: number;
   callParticipantsMax: number;
   callDuration: number;
+  encryption: EncryptionScheme;
+  toDeviceEncryptionKeysSent: number;
+  toDeviceEncryptionKeysReceived: number;
+  toDeviceEncryptionKeysReceivedAverageAge: number;
+  roomEventEncryptionKeysSent: number;
+  roomEventEncryptionKeysReceived: number;
+  roomEventEncryptionKeysReceivedAverageAge: number;
 }
 
 export class CallEndedTracker {
@@ -51,6 +72,8 @@ export class CallEndedTracker {
   public track(
     callId: string,
     callParticipantsNow: number,
+    e2eeType: E2eeType,
+    rtcSession: MatrixRTCSession,
     sendInstantly: boolean,
   ): void {
     PosthogAnalytics.instance.trackEvent<CallEnded>(
@@ -60,6 +83,27 @@ export class CallEndedTracker {
         callParticipantsMax: this.cache.maxParticipantsCount,
         callParticipantsOnLeave: callParticipantsNow,
         callDuration: (Date.now() - this.cache.startTime.getTime()) / 1000,
+        encryption: mapE2eeType(e2eeType),
+        toDeviceEncryptionKeysSent:
+          rtcSession.statistics.counters.toDeviceEncryptionKeysSent,
+        toDeviceEncryptionKeysReceived:
+          rtcSession.statistics.counters.toDeviceEncryptionKeysReceived,
+        toDeviceEncryptionKeysReceivedAverageAge:
+          rtcSession.statistics.counters.toDeviceEncryptionKeysReceived > 0
+            ? rtcSession.statistics.totals
+                .toDeviceEncryptionKeysReceivedTotalAge /
+              rtcSession.statistics.counters.toDeviceEncryptionKeysReceived
+            : 0,
+        roomEventEncryptionKeysSent:
+          rtcSession.statistics.counters.roomEventEncryptionKeysSent,
+        roomEventEncryptionKeysReceived:
+          rtcSession.statistics.counters.roomEventEncryptionKeysReceived,
+        roomEventEncryptionKeysReceivedAverageAge:
+          rtcSession.statistics.counters.roomEventEncryptionKeysReceived > 0
+            ? rtcSession.statistics.totals
+                .roomEventEncryptionKeysReceivedTotalAge /
+              rtcSession.statistics.counters.roomEventEncryptionKeysReceived
+            : 0,
       },
       { send_instantly: sendInstantly },
     );
@@ -69,13 +113,15 @@ export class CallEndedTracker {
 interface CallStarted extends IPosthogEvent {
   eventName: "CallStarted";
   callId: string;
+  encryption: EncryptionScheme;
 }
 
 export class CallStartedTracker {
-  public track(callId: string): void {
+  public track(callId: string, e2eeType: E2eeType): void {
     PosthogAnalytics.instance.trackEvent<CallStarted>({
       eventName: "CallStarted",
       callId: callId,
+      encryption: mapE2eeType(e2eeType),
     });
   }
 }
diff --git a/src/home/RegisteredView.tsx b/src/home/RegisteredView.tsx
index 3335acd2..70aea754 100644
--- a/src/home/RegisteredView.tsx
+++ b/src/home/RegisteredView.tsx
@@ -18,7 +18,7 @@ import { useState, useCallback, FormEvent, FormEventHandler, FC } from "react";
 import { useHistory } from "react-router-dom";
 import { MatrixClient } from "matrix-js-sdk/src/client";
 import { useTranslation } from "react-i18next";
-import { Heading } from "@vector-im/compound-web";
+import { Dropdown, Heading } from "@vector-im/compound-web";
 import { logger } from "matrix-js-sdk/src/logger";
 import { Button } from "@vector-im/compound-web";
 
@@ -45,6 +45,17 @@ import { useOptInAnalytics } from "../settings/settings";
 interface Props {
   client: MatrixClient;
 }
+const encryptionOptions = {
+  shared: {
+    label: "Shared key",
+    e2eeType: E2eeType.SHARED_KEY,
+  },
+  sender: {
+    label: "Per-participant key",
+    e2eeType: E2eeType.PER_PARTICIPANT,
+  },
+  none: { label: "None", e2eeType: E2eeType.NONE },
+};
 
 export const RegisteredView: FC<Props> = ({ client }) => {
   const [loading, setLoading] = useState(false);
@@ -59,6 +70,9 @@ export const RegisteredView: FC<Props> = ({ client }) => {
     [setJoinExistingCallModalOpen],
   );
 
+  const [encryption, setEncryption] =
+    useState<keyof typeof encryptionOptions>("shared");
+
   const onSubmit: FormEventHandler<HTMLFormElement> = useCallback(
     (e: FormEvent) => {
       e.preventDefault();
@@ -73,21 +87,13 @@ export const RegisteredView: FC<Props> = ({ client }) => {
         setError(undefined);
         setLoading(true);
 
-        const createRoomResult = await createRoom(
+        const { roomId, encryptionSystem } = await createRoom(
           client,
           roomName,
-          E2eeType.SHARED_KEY,
+          encryptionOptions[encryption].e2eeType,
         );
-        if (!createRoomResult.password)
-          throw new Error("Failed to create room with shared secret");
 
-        history.push(
-          getRelativeRoomUrl(
-            createRoomResult.roomId,
-            { kind: E2eeType.SHARED_KEY, secret: createRoomResult.password },
-            roomName,
-          ),
-        );
+        history.push(getRelativeRoomUrl(roomId, encryptionSystem, roomName));
       }
 
       submit().catch((error) => {
@@ -103,7 +109,7 @@ export const RegisteredView: FC<Props> = ({ client }) => {
         }
       });
     },
-    [client, history, setJoinExistingCallModalOpen],
+    [client, history, setJoinExistingCallModalOpen, encryption],
   );
 
   const recentRooms = useGroupCallRooms(client);
@@ -142,6 +148,19 @@ export const RegisteredView: FC<Props> = ({ client }) => {
                 data-testid="home_callName"
               />
 
+              <Dropdown
+                label="Encryption"
+                defaultValue={encryption}
+                onValueChange={(x) =>
+                  setEncryption(x as keyof typeof encryptionOptions)
+                }
+                values={Object.keys(encryptionOptions).map((value) => [
+                  value,
+                  encryptionOptions[value as keyof typeof encryptionOptions]
+                    .label,
+                ])}
+                placeholder=""
+              />
               <Button
                 type="submit"
                 size="lg"
diff --git a/src/home/UnauthenticatedView.tsx b/src/home/UnauthenticatedView.tsx
index ae222737..8b0ce13c 100644
--- a/src/home/UnauthenticatedView.tsx
+++ b/src/home/UnauthenticatedView.tsx
@@ -18,7 +18,7 @@ import { FC, useCallback, useState, FormEventHandler } from "react";
 import { useHistory } from "react-router-dom";
 import { randomString } from "matrix-js-sdk/src/randomstring";
 import { Trans, useTranslation } from "react-i18next";
-import { Button, Heading } from "@vector-im/compound-web";
+import { Button, Dropdown, Heading } from "@vector-im/compound-web";
 import { logger } from "matrix-js-sdk/src/logger";
 
 import { useClient } from "../ClientContext";
@@ -44,6 +44,18 @@ import { Config } from "../config/Config";
 import { E2eeType } from "../e2ee/e2eeType";
 import { useOptInAnalytics } from "../settings/settings";
 
+const encryptionOptions = {
+  shared: {
+    label: "Shared key",
+    e2eeType: E2eeType.SHARED_KEY,
+  },
+  sender: {
+    label: "Per-participant key",
+    e2eeType: E2eeType.PER_PARTICIPANT,
+  },
+  none: { label: "None", e2eeType: E2eeType.NONE },
+};
+
 export const UnauthenticatedView: FC = () => {
   const { setClient } = useClient();
   const [loading, setLoading] = useState(false);
@@ -52,6 +64,9 @@ export const UnauthenticatedView: FC = () => {
   const { recaptchaKey, register } = useInteractiveRegistration();
   const { execute, reset, recaptchaId } = useRecaptcha(recaptchaKey);
 
+  const [encryption, setEncryption] =
+    useState<keyof typeof encryptionOptions>("shared");
+
   const [joinExistingCallModalOpen, setJoinExistingCallModalOpen] =
     useState(false);
   const onDismissJoinExistingCallModal = useCallback(
@@ -82,13 +97,16 @@ export const UnauthenticatedView: FC = () => {
           true,
         );
 
-        let createRoomResult;
+        let roomId;
+        let encryptionSystem;
         try {
-          createRoomResult = await createRoom(
+          const res = await createRoom(
             client,
             roomName,
-            E2eeType.SHARED_KEY,
+            encryptionOptions[encryption].e2eeType,
           );
+          roomId = res.roomId;
+          encryptionSystem = res.encryptionSystem;
         } catch (error) {
           if (!setClient) {
             throw error;
@@ -115,17 +133,11 @@ export const UnauthenticatedView: FC = () => {
         if (!setClient) {
           throw new Error("setClient is undefined");
         }
-        if (!createRoomResult.password)
-          throw new Error("Failed to create room with shared secret");
+        // if (!createRoomResult.password)
+        //   throw new Error("Failed to create room with shared secret");
 
         setClient({ client, session });
-        history.push(
-          getRelativeRoomUrl(
-            createRoomResult.roomId,
-            { kind: E2eeType.SHARED_KEY, secret: createRoomResult.password },
-            roomName,
-          ),
-        );
+        history.push(getRelativeRoomUrl(roomId, encryptionSystem, roomName));
       }
 
       submit().catch((error) => {
@@ -142,6 +154,7 @@ export const UnauthenticatedView: FC = () => {
       history,
       setJoinExistingCallModalOpen,
       setClient,
+      encryption,
     ],
   );
 
@@ -204,6 +217,20 @@ export const UnauthenticatedView: FC = () => {
                 <ErrorMessage error={error} />
               </FieldRow>
             )}
+            <Dropdown
+              label="Encryption"
+              defaultValue={encryption}
+              onValueChange={(x) =>
+                setEncryption(x as keyof typeof encryptionOptions)
+              }
+              values={Object.keys(encryptionOptions).map((value) => [
+                value,
+                encryptionOptions[value as keyof typeof encryptionOptions]
+                  .label,
+              ])}
+              placeholder=""
+            />
+
             <Button
               type="submit"
               size="lg"
diff --git a/src/room/GroupCallView.tsx b/src/room/GroupCallView.tsx
index 8339e749..7e9e3d60 100644
--- a/src/room/GroupCallView.tsx
+++ b/src/room/GroupCallView.tsx
@@ -97,7 +97,7 @@ export const GroupCallView: FC<Props> = ({
   const { displayName, avatarUrl } = useProfile(client);
   const roomName = useRoomName(rtcSession.room);
   const roomAvatar = useRoomAvatar(rtcSession.room);
-  const { perParticipantE2EE, returnToLobby } = useUrlParams();
+  const { returnToLobby } = useUrlParams();
   const e2eeSystem = useRoomEncryptionSystem(rtcSession.room.roomId);
 
   const matrixInfo = useMemo((): MatrixInfo => {
@@ -191,7 +191,7 @@ export const GroupCallView: FC<Props> = ({
         ev: CustomEvent<IWidgetApiRequest>,
       ): Promise<void> => {
         await defaultDeviceSetup(ev.detail.data as unknown as JoinCallData);
-        await enterRTCSession(rtcSession, perParticipantE2EE);
+        await enterRTCSession(rtcSession, e2eeSystem.kind);
         await widget!.api.transport.reply(ev.detail, {});
       };
       widget.lazyActions.on(ElementWidgetActions.JoinCall, onJoin);
@@ -201,12 +201,12 @@ export const GroupCallView: FC<Props> = ({
     } else if (widget && !preload && skipLobby) {
       const join = async (): Promise<void> => {
         await defaultDeviceSetup({ audioInput: null, videoInput: null });
-        await enterRTCSession(rtcSession, perParticipantE2EE);
+        await enterRTCSession(rtcSession, e2eeSystem.kind);
       };
       // No lobby and no preload: we enter the RTC Session right away.
       join();
     }
-  }, [rtcSession, preload, skipLobby, perParticipantE2EE]);
+  }, [rtcSession, preload, skipLobby, e2eeSystem]);
 
   const [left, setLeft] = useState(false);
   const [leaveError, setLeaveError] = useState<Error | undefined>(undefined);
@@ -223,6 +223,8 @@ export const GroupCallView: FC<Props> = ({
       PosthogAnalytics.instance.eventCallEnded.track(
         rtcSession.room.roomId,
         rtcSession.memberships.length,
+        matrixInfo.e2eeSystem.kind,
+        rtcSession,
         sendInstantly,
       );
 
@@ -237,7 +239,7 @@ export const GroupCallView: FC<Props> = ({
         history.push("/");
       }
     },
-    [rtcSession, isPasswordlessUser, confineToRoom, history],
+    [rtcSession, isPasswordlessUser, confineToRoom, history, matrixInfo],
   );
 
   useEffect(() => {
@@ -262,8 +264,8 @@ export const GroupCallView: FC<Props> = ({
   const onReconnect = useCallback(() => {
     setLeft(false);
     setLeaveError(undefined);
-    enterRTCSession(rtcSession, perParticipantE2EE);
-  }, [rtcSession, perParticipantE2EE]);
+    enterRTCSession(rtcSession, e2eeSystem.kind);
+  }, [rtcSession, e2eeSystem]);
 
   const joinRule = useJoinRule(rtcSession.room);
 
@@ -316,7 +318,7 @@ export const GroupCallView: FC<Props> = ({
         client={client}
         matrixInfo={matrixInfo}
         muteStates={muteStates}
-        onEnter={() => void enterRTCSession(rtcSession, perParticipantE2EE)}
+        onEnter={() => void enterRTCSession(rtcSession, e2eeSystem.kind)}
         confineToRoom={confineToRoom}
         hideHeader={hideHeader}
         participantCount={participantCount}
diff --git a/src/rtcSessionHelper.test.ts b/src/rtcSessionHelper.test.ts
index fc00aa61..0c43d6c8 100644
--- a/src/rtcSessionHelper.test.ts
+++ b/src/rtcSessionHelper.test.ts
@@ -19,6 +19,7 @@ import { expect, test, vi } from "vitest";
 
 import { enterRTCSession } from "../src/rtcSessionHelpers";
 import { Config } from "../src/config/Config";
+import { E2eeType } from "../src/e2ee/e2eeType";
 
 test("It joins the correct Session", async () => {
   const focusFromOlderMembership = {
@@ -60,7 +61,7 @@ test("It joins the correct Session", async () => {
     }),
     joinRoomSession: vi.fn(),
   }) as unknown as MatrixRTCSession;
-  await enterRTCSession(mockedSession, false);
+  await enterRTCSession(mockedSession, E2eeType.NONE);
 
   expect(mockedSession.joinRoomSession).toHaveBeenLastCalledWith(
     [
diff --git a/src/rtcSessionHelpers.ts b/src/rtcSessionHelpers.ts
index 451871ea..d3fe4ecf 100644
--- a/src/rtcSessionHelpers.ts
+++ b/src/rtcSessionHelpers.ts
@@ -26,6 +26,7 @@ import {
 import { PosthogAnalytics } from "./analytics/PosthogAnalytics";
 import { Config } from "./config/Config";
 import { ElementWidgetActions, WidgetHelpers, widget } from "./widget";
+import { E2eeType } from "./e2ee/e2eeType";
 
 const FOCI_WK_KEY = "org.matrix.msc4143.rtc_foci";
 
@@ -97,10 +98,13 @@ async function makePreferredLivekitFoci(
 
 export async function enterRTCSession(
   rtcSession: MatrixRTCSession,
-  encryptMedia: boolean,
+  e2eeType: E2eeType,
 ): Promise<void> {
   PosthogAnalytics.instance.eventCallEnded.cacheStartCall(new Date());
-  PosthogAnalytics.instance.eventCallStarted.track(rtcSession.room.roomId);
+  PosthogAnalytics.instance.eventCallStarted.track(
+    rtcSession.room.roomId,
+    e2eeType,
+  );
 
   // This must be called before we start trying to join the call, as we need to
   // have started tracking by the time calls start getting created.
@@ -114,7 +118,7 @@ export async function enterRTCSession(
     await makePreferredLivekitFoci(rtcSession, livekitAlias),
     makeActiveFocus(),
     {
-      manageMediaKeys: encryptMedia,
+      manageMediaKeys: e2eeType === E2eeType.PER_PARTICIPANT,
       ...(useDeviceSessionMemberEvents !== undefined && {
         useLegacyMemberEvents: !useDeviceSessionMemberEvents,
       }),
diff --git a/src/state/CallViewModel.ts b/src/state/CallViewModel.ts
index 144b0937..de662455 100644
--- a/src/state/CallViewModel.ts
+++ b/src/state/CallViewModel.ts
@@ -173,11 +173,24 @@ class UserMedia {
     member: RoomMember | undefined,
     participant: LocalParticipant | RemoteParticipant,
     callEncrypted: boolean,
+    livekitRoom: LivekitRoom,
   ) {
     this.vm =
       participant instanceof LocalParticipant
-        ? new LocalUserMediaViewModel(id, member, participant, callEncrypted)
-        : new RemoteUserMediaViewModel(id, member, participant, callEncrypted);
+        ? new LocalUserMediaViewModel(
+            id,
+            member,
+            participant,
+            callEncrypted,
+            livekitRoom,
+          )
+        : new RemoteUserMediaViewModel(
+            id,
+            member,
+            participant,
+            callEncrypted,
+            livekitRoom,
+          );
 
     this.speaker = this.vm.speaking.pipe(
       // Require 1 s of continuous speaking to become a speaker, and 60 s of
@@ -219,8 +232,15 @@ class ScreenShare {
     member: RoomMember | undefined,
     participant: LocalParticipant | RemoteParticipant,
     callEncrypted: boolean,
+    liveKitRoom: LivekitRoom,
   ) {
-    this.vm = new ScreenShareViewModel(id, member, participant, callEncrypted);
+    this.vm = new ScreenShareViewModel(
+      id,
+      member,
+      participant,
+      callEncrypted,
+      liveKitRoom,
+    );
   }
 
   public destroy(): void {
@@ -353,7 +373,13 @@ export class CallViewModel extends ViewModel {
                 yield [
                   userMediaId,
                   prevItems.get(userMediaId) ??
-                    new UserMedia(userMediaId, member, p, this.encrypted),
+                    new UserMedia(
+                      userMediaId,
+                      member,
+                      p,
+                      this.encrypted,
+                      this.livekitRoom,
+                    ),
                 ];
 
                 if (p.isScreenShareEnabled) {
@@ -361,7 +387,13 @@ export class CallViewModel extends ViewModel {
                   yield [
                     screenShareId,
                     prevItems.get(screenShareId) ??
-                      new ScreenShare(screenShareId, member, p, this.encrypted),
+                      new ScreenShare(
+                        screenShareId,
+                        member,
+                        p,
+                        this.encrypted,
+                        this.livekitRoom,
+                      ),
                   ];
                 }
               }
diff --git a/src/state/MediaViewModel.ts b/src/state/MediaViewModel.ts
index ff262996..750815d4 100644
--- a/src/state/MediaViewModel.ts
+++ b/src/state/MediaViewModel.ts
@@ -20,6 +20,7 @@ import {
   VideoSource,
   observeParticipantEvents,
   observeParticipantMedia,
+  roomEventSelector,
 } from "@livekit/components-core";
 import {
   LocalParticipant,
@@ -30,18 +31,25 @@ import {
   Track,
   TrackEvent,
   facingModeFromLocalTrack,
+  Room as LivekitRoom,
+  RoomEvent as LivekitRoomEvent,
 } from "livekit-client";
 import { RoomMember, RoomMemberEvent } from "matrix-js-sdk/src/matrix";
 import {
   BehaviorSubject,
   Observable,
   combineLatest,
+  debounceTime,
+  distinctUntilChanged,
   distinctUntilKeyChanged,
   fromEvent,
   map,
+  merge,
   of,
+  shareReplay,
   startWith,
   switchMap,
+  throttleTime,
 } from "rxjs";
 import { useEffect } from "react";
 
@@ -85,6 +93,35 @@ function observeTrackReference(
   );
 }
 
+function encryptionErrorObservable(
+  room: LivekitRoom,
+  participant: Participant,
+  criteria: string,
+): Observable<boolean> {
+  const roomEvents = roomEventSelector(
+    room,
+    LivekitRoomEvent.EncryptionError,
+  ).pipe(
+    map((e) => {
+      // eslint-disable-next-line @typescript-eslint/no-explicit-any
+      const [err, participantIdentity] = e as any; // FIXME: fudge for type error during build
+      return (
+        (participantIdentity == participant.identity &&
+          err?.message.includes(criteria)) ??
+        false
+      );
+    }),
+    throttleTime(1000), // Throttle to avoid spamming the UI
+  );
+
+  return merge(
+    roomEvents,
+    roomEvents.pipe(
+      debounceTime(3000), // Wait 3 seconds before clearing the error, toast style
+      map(() => false),
+    ),
+  );
+}
 abstract class BaseMediaViewModel extends ViewModel {
   /**
    * Whether the media belongs to the local user.
@@ -99,6 +136,10 @@ abstract class BaseMediaViewModel extends ViewModel {
    */
   public readonly unencryptedWarning: Observable<boolean>;
 
+  public readonly encryptionKeyMissing: Observable<boolean>;
+
+  public readonly encryptionKeyInvalid: Observable<boolean>;
+
   public constructor(
     /**
      * An opaque identifier for this media.
@@ -110,10 +151,11 @@ abstract class BaseMediaViewModel extends ViewModel {
     // TODO: Fully separate the data layer from the UI layer by keeping the
     // member object internal
     public readonly member: RoomMember | undefined,
-    protected readonly participant: LocalParticipant | RemoteParticipant,
+    public readonly participant: LocalParticipant | RemoteParticipant,
     callEncrypted: boolean,
     audioSource: AudioSource,
     videoSource: VideoSource,
+    livekitRoom: LivekitRoom,
   ) {
     super();
     const audio = observeTrackReference(participant, audioSource).pipe(
@@ -128,7 +170,17 @@ abstract class BaseMediaViewModel extends ViewModel {
         callEncrypted &&
         (a.publication?.isEncrypted === false ||
           v.publication?.isEncrypted === false),
-    ).pipe(this.scope.state());
+    ).pipe(distinctUntilChanged(), shareReplay(1));
+    this.encryptionKeyMissing = encryptionErrorObservable(
+      livekitRoom,
+      participant,
+      "MissingKey",
+    ).pipe(startWith(false));
+    this.encryptionKeyInvalid = encryptionErrorObservable(
+      livekitRoom,
+      participant,
+      "InvalidKey",
+    ).pipe(startWith(false));
   }
 }
 
@@ -175,6 +227,7 @@ abstract class BaseUserMediaViewModel extends BaseMediaViewModel {
     member: RoomMember | undefined,
     participant: LocalParticipant | RemoteParticipant,
     callEncrypted: boolean,
+    livekitRoom: LivekitRoom,
   ) {
     super(
       id,
@@ -183,6 +236,7 @@ abstract class BaseUserMediaViewModel extends BaseMediaViewModel {
       callEncrypted,
       Track.Source.Microphone,
       Track.Source.Camera,
+      livekitRoom,
     );
 
     const media = observeParticipantMedia(participant).pipe(this.scope.state());
@@ -232,8 +286,9 @@ export class LocalUserMediaViewModel extends BaseUserMediaViewModel {
     member: RoomMember | undefined,
     participant: LocalParticipant,
     callEncrypted: boolean,
+    livekitRoom: LivekitRoom,
   ) {
-    super(id, member, participant, callEncrypted);
+    super(id, member, participant, callEncrypted, livekitRoom);
   }
 }
 
@@ -259,8 +314,9 @@ export class RemoteUserMediaViewModel extends BaseUserMediaViewModel {
     member: RoomMember | undefined,
     participant: RemoteParticipant,
     callEncrypted: boolean,
+    livekitRoom: LivekitRoom,
   ) {
-    super(id, member, participant, callEncrypted);
+    super(id, member, participant, callEncrypted, livekitRoom);
 
     // Sync the local mute state and volume with LiveKit
     combineLatest([this._locallyMuted, this._localVolume], (muted, volume) =>
@@ -290,6 +346,7 @@ export class ScreenShareViewModel extends BaseMediaViewModel {
     member: RoomMember | undefined,
     participant: LocalParticipant | RemoteParticipant,
     callEncrypted: boolean,
+    livekitRoom: LivekitRoom,
   ) {
     super(
       id,
@@ -298,6 +355,7 @@ export class ScreenShareViewModel extends BaseMediaViewModel {
       callEncrypted,
       Track.Source.ScreenShareAudio,
       Track.Source.ScreenShare,
+      livekitRoom,
     );
   }
 }
diff --git a/src/tile/GridTile.tsx b/src/tile/GridTile.tsx
index 01e0f420..c421032c 100644
--- a/src/tile/GridTile.tsx
+++ b/src/tile/GridTile.tsx
@@ -19,6 +19,7 @@ import {
   ReactNode,
   forwardRef,
   useCallback,
+  useMemo,
   useState,
 } from "react";
 import { animated } from "@react-spring/web";
@@ -88,6 +89,12 @@ const UserMediaTile = forwardRef<HTMLDivElement, UserMediaTileProps>(
     const { t } = useTranslation();
     const video = useObservableEagerState(vm.video);
     const unencryptedWarning = useObservableEagerState(vm.unencryptedWarning);
+    const encryptionKeyMissing = useObservableEagerState(
+      vm.encryptionKeyMissing,
+    );
+    const encryptionKeyInvalid = useObservableEagerState(
+      vm.encryptionKeyInvalid,
+    );
     const audioEnabled = useObservableEagerState(vm.audioEnabled);
     const videoEnabled = useObservableEagerState(vm.videoEnabled);
     const speaking = useObservableEagerState(vm.speaking);
@@ -100,6 +107,8 @@ const UserMediaTile = forwardRef<HTMLDivElement, UserMediaTileProps>(
       [vm],
     );
 
+    const participantId = useMemo(() => vm.participant.identity, [vm]);
+
     const MicIcon = audioEnabled ? MicOnSolidIcon : MicOffSolidIcon;
 
     const [menuOpen, setMenuOpen] = useState(false);
@@ -122,6 +131,9 @@ const UserMediaTile = forwardRef<HTMLDivElement, UserMediaTileProps>(
         video={video}
         member={vm.member}
         unencryptedWarning={unencryptedWarning}
+        encryptionKeyMissing={encryptionKeyMissing}
+        encryptionKeyInvalid={encryptionKeyInvalid}
+        participantId={participantId}
         videoEnabled={videoEnabled && showVideo}
         videoFit={cropVideo ? "cover" : "contain"}
         className={classNames(className, styles.tile, {
diff --git a/src/tile/MediaView.module.css b/src/tile/MediaView.module.css
index a9037977..f54b1ef6 100644
--- a/src/tile/MediaView.module.css
+++ b/src/tile/MediaView.module.css
@@ -94,7 +94,7 @@ unconditionally select the container so we can use cqmin units */
   display: grid;
   grid-template-columns: 1fr auto;
   grid-template-rows: 1fr auto;
-  grid-template-areas: ". ." "nameTag button";
+  grid-template-areas: "status status" "nameTag button";
   gap: var(--cpd-space-1x);
   place-items: start;
 }
@@ -115,6 +115,24 @@ unconditionally select the container so we can use cqmin units */
   max-inline-size: 100%;
 }
 
+.status {
+  grid-area: status;
+  justify-self: center;
+  align-self: start;
+  padding: var(--cpd-space-1x);
+  padding-block: var(--cpd-space-1x);
+  color: var(--cpd-color-text-primary);
+  background-color: var(--cpd-color-bg-canvas-default);
+  display: flex;
+  align-items: center;
+  border-radius: var(--cpd-radius-pill-effect);
+  user-select: none;
+  overflow: hidden;
+  box-shadow: var(--small-drop-shadow);
+  box-sizing: border-box;
+  max-inline-size: 100%;
+}
+
 .nameTag > svg,
 .nameTag > span {
   flex-shrink: 0;
diff --git a/src/tile/MediaView.tsx b/src/tile/MediaView.tsx
index 4d073092..651b31aa 100644
--- a/src/tile/MediaView.tsx
+++ b/src/tile/MediaView.tsx
@@ -38,8 +38,11 @@ interface Props extends ComponentProps<typeof animated.div> {
   member: RoomMember | undefined;
   videoEnabled: boolean;
   unencryptedWarning: boolean;
+  encryptionKeyMissing: boolean;
+  encryptionKeyInvalid: boolean;
   nameTagLeadingIcon?: ReactNode;
   displayName: string;
+  participantId: string;
   primaryButton?: ReactNode;
 }
 
@@ -59,6 +62,9 @@ export const MediaView = forwardRef<HTMLDivElement, Props>(
       nameTagLeadingIcon,
       displayName,
       primaryButton,
+      encryptionKeyMissing,
+      encryptionKeyInvalid,
+      participantId,
       ...props
     },
     ref,
@@ -69,7 +75,8 @@ export const MediaView = forwardRef<HTMLDivElement, Props>(
       <animated.div
         className={classNames(styles.media, className, {
           [styles.mirror]: mirror,
-          [styles.videoMuted]: !videoEnabled,
+          [styles.videoMuted]:
+            !videoEnabled || encryptionKeyInvalid || encryptionKeyMissing,
         })}
         style={style}
         ref={ref}
@@ -95,10 +102,24 @@ export const MediaView = forwardRef<HTMLDivElement, Props>(
           )}
         </div>
         <div className={styles.fg}>
-          <div className={styles.nameTag}>
+          {encryptionKeyMissing && (
+            <div className={styles.status}>
+              <Text as="span" size="sm" weight="medium" className={styles.name}>
+                Encryption key missing
+              </Text>
+            </div>
+          )}
+          {encryptionKeyInvalid && (
+            <div className={styles.status}>
+              <Text as="span" size="sm" weight="medium" className={styles.name}>
+                Encryption key invalid
+              </Text>
+            </div>
+          )}
+          <div className={styles.nameTag} title={participantId}>
             {nameTagLeadingIcon}
             <Text as="span" size="sm" weight="medium" className={styles.name}>
-              {displayName}
+              {displayName} ({participantId})
             </Text>
             {unencryptedWarning && (
               <Tooltip
diff --git a/src/tile/SpotlightTile.tsx b/src/tile/SpotlightTile.tsx
index f920d01e..af68cabc 100644
--- a/src/tile/SpotlightTile.tsx
+++ b/src/tile/SpotlightTile.tsx
@@ -20,6 +20,7 @@ import {
   forwardRef,
   useCallback,
   useEffect,
+  useMemo,
   useRef,
   useState,
 } from "react";
@@ -60,7 +61,10 @@ interface SpotlightItemBaseProps {
   video: TrackReferenceOrPlaceholder;
   member: RoomMember | undefined;
   unencryptedWarning: boolean;
+  encryptionKeyMissing: boolean;
+  encryptionKeyInvalid: boolean;
   displayName: string;
+  participantId: string;
 }
 
 interface SpotlightUserMediaItemBaseProps extends SpotlightItemBaseProps {
@@ -127,6 +131,17 @@ const SpotlightItem = forwardRef<HTMLDivElement, SpotlightItemProps>(
     const displayName = useDisplayName(vm);
     const video = useObservableEagerState(vm.video);
     const unencryptedWarning = useObservableEagerState(vm.unencryptedWarning);
+    const encryptionKeyMissing = useObservableEagerState(
+      vm.encryptionKeyMissing,
+    );
+    const encryptionKeyInvalid = useObservableEagerState(
+      vm.encryptionKeyInvalid,
+    );
+
+    const participantId = useMemo(
+      () => vm.participant.identity,
+      [vm.participant],
+    );
 
     // Hook this item up to the intersection observer
     useEffect(() => {
@@ -153,6 +168,9 @@ const SpotlightItem = forwardRef<HTMLDivElement, SpotlightItemProps>(
       member: vm.member,
       unencryptedWarning,
       displayName,
+      encryptionKeyMissing,
+      encryptionKeyInvalid,
+      participantId,
     };
 
     return vm instanceof ScreenShareViewModel ? (
diff --git a/src/utils/matrix.ts b/src/utils/matrix.ts
index f27067bf..0ad1097b 100644
--- a/src/utils/matrix.ts
+++ b/src/utils/matrix.ts
@@ -18,6 +18,7 @@ import { IndexedDBStore } from "matrix-js-sdk/src/store/indexeddb";
 import { MemoryStore } from "matrix-js-sdk/src/store/memory";
 import {
   createClient,
+  EventType,
   ICreateClientOpts,
   Preset,
   Visibility,
@@ -217,7 +218,7 @@ export function sanitiseRoomNameInput(input: string): string {
 interface CreateRoomResult {
   roomId: string;
   alias?: string;
-  password?: string;
+  encryptionSystem: EncryptionSystem;
 }
 
 /**
@@ -264,6 +265,18 @@ export async function createRoom(
         [client.getUserId()!]: 100,
       },
     },
+    initial_state:
+      e2ee === E2eeType.PER_PARTICIPANT
+        ? [
+            {
+              type: EventType.RoomEncryption,
+              state_key: "",
+              content: {
+                algorithm: "m.megolm.v1.aes-sha2",
+              },
+            },
+          ]
+        : undefined,
   });
 
   // Wait for the room to arrive
@@ -287,16 +300,22 @@ export async function createRoom(
 
   const result = await createPromise;
 
-  let password;
+  let encryptionSystem: EncryptionSystem;
   if (e2ee == E2eeType.SHARED_KEY) {
-    password = secureRandomBase64Url(16);
+    const password = secureRandomBase64Url(16);
     saveKeyForRoom(result.room_id, password);
+    encryptionSystem = {
+      kind: E2eeType.SHARED_KEY,
+      secret: password,
+    };
+  } else {
+    encryptionSystem = { kind: e2ee };
   }
 
   return {
     roomId: result.room_id,
     alias: e2ee ? undefined : fullAliasFromRoomName(name, client),
-    password,
+    encryptionSystem,
   };
 }