diff --git a/Signal/src/ViewControllers/DebugUI/DebugUIMisc.m b/Signal/src/ViewControllers/DebugUI/DebugUIMisc.m
index bffd48f61..0bdea418c 100644
--- a/Signal/src/ViewControllers/DebugUI/DebugUIMisc.m
+++ b/Signal/src/ViewControllers/DebugUI/DebugUIMisc.m
@@ -17,6 +17,7 @@
 #import <SignalServiceKit/TSCall.h>
 #import <SignalServiceKit/TSInvalidIdentityKeyReceivingErrorMessage.h>
 #import <SignalServiceKit/TSStorageManager+SessionStore.h>
+#import <SignalServiceKit/OWSProfileKeyMessage.h>
 #import <SignalServiceKit/TSThread.h>
 
 NS_ASSUME_NONNULL_BEGIN
@@ -67,6 +68,18 @@ NS_ASSUME_NONNULL_BEGIN
                                          [[OWSProfileManager sharedManager] regenerateLocalProfile];
                                      }]];
 #endif
+    [items addObject:[OWSTableItem itemWithTitle:@"Send profile key message."
+                                     actionBlock:^{
+                                         OWSProfileKeyMessage *message = [[OWSProfileKeyMessage alloc] initWithTimestamp:[NSDate ows_millisecondTimeStamp] inThread:thread];
+                                         
+                                         [[Environment getCurrent].messageSender sendMessage:message
+                                                                                     success:^{
+                                                                                         DDLogInfo(@"Successfully sent profile key message to thread: %@", thread);
+                                                                                     }
+                                                                                     failure:^(NSError * _Nonnull error) {
+                                                                                         OWSFail(@"Failed to send prifle key message to thread: %@", thread);
+                                                                                     }];
+                                     }]];
     [items addObject:[OWSTableItem itemWithTitle:@"Clear hasDismissedOffers"
                                      actionBlock:^{
                                          [DebugUIMisc clearHasDismissedOffers];
diff --git a/SignalServiceKit/protobuf/OWSSignalServiceProtos.proto b/SignalServiceKit/protobuf/OWSSignalServiceProtos.proto
index b7143f49c..127564f86 100644
--- a/SignalServiceKit/protobuf/OWSSignalServiceProtos.proto
+++ b/SignalServiceKit/protobuf/OWSSignalServiceProtos.proto
@@ -82,6 +82,7 @@ message DataMessage {
   enum Flags {
     END_SESSION = 1;
     EXPIRATION_TIMER_UPDATE = 2;
+    PROFILE_KEY = 4;
   }
 
   optional string             body        = 1;
diff --git a/SignalServiceKit/src/Messages/OWSProfileKeyMessage.h b/SignalServiceKit/src/Messages/OWSProfileKeyMessage.h
new file mode 100644
index 000000000..cd8c4d73a
--- /dev/null
+++ b/SignalServiceKit/src/Messages/OWSProfileKeyMessage.h
@@ -0,0 +1,13 @@
+//
+//  Copyright (c) 2017 Open Whisper Systems. All rights reserved.
+//
+
+#import "TSOutgoingMessage.h"
+
+NS_ASSUME_NONNULL_BEGIN
+
+@interface OWSProfileKeyMessage : TSOutgoingMessage
+
+@end
+
+NS_ASSUME_NONNULL_END
diff --git a/SignalServiceKit/src/Messages/OWSProfileKeyMessage.m b/SignalServiceKit/src/Messages/OWSProfileKeyMessage.m
new file mode 100644
index 000000000..06af08c8c
--- /dev/null
+++ b/SignalServiceKit/src/Messages/OWSProfileKeyMessage.m
@@ -0,0 +1,50 @@
+//
+//  Copyright (c) 2017 Open Whisper Systems. All rights reserved.
+//
+
+#import "OWSProfileKeyMessage.h"
+#import "OWSSignalServiceProtos.pb.h"
+#import "ProfileManagerProtocol.h"
+#import "ProtoBuf+OWS.h"
+#import "TextSecureKitEnv.h"
+
+NS_ASSUME_NONNULL_BEGIN
+
+@implementation OWSProfileKeyMessage
+
+- (void)saveWithTransaction:(YapDatabaseReadWriteTransaction *)transaction
+{
+    // override superclass with no-op.
+    //
+    // There's no need to save this message, since it's not displayed to the user.
+}
+
+- (BOOL)shouldSyncTranscript
+{
+    return NO;
+}
+
+- (OWSSignalServiceProtosDataMessage *)buildDataMessage:(NSString *_Nullable)recipientId
+{
+    OWSAssert(self.thread);
+    
+    OWSSignalServiceProtosDataMessageBuilder *builder = [self dataMessageBuilder];
+    [builder addLocalProfileKey];
+    [builder setFlags:OWSSignalServiceProtosDataMessageFlagsProfileKey];
+    
+    if (recipientId.length > 0) {
+        // Once we've shared our profile key with a user (perhaps due to being
+        // a member of a whitelisted group), make sure they're whitelisted.
+        id<ProfileManagerProtocol> profileManager = [TextSecureKitEnv sharedEnv].profileManager;
+        // FIXME PERF avoid this dispatch. It's going to happen for *each* recipient in a group message.
+        dispatch_async(dispatch_get_main_queue(), ^{
+            [profileManager addUserToProfileWhitelist:recipientId];
+        });
+    }
+
+    return [builder build];
+}
+
+@end
+
+NS_ASSUME_NONNULL_END
diff --git a/SignalServiceKit/src/Messages/OWSSignalServiceProtos.pb.h b/SignalServiceKit/src/Messages/OWSSignalServiceProtos.pb.h
index af214bbde..37430bee2 100644
--- a/SignalServiceKit/src/Messages/OWSSignalServiceProtos.pb.h
+++ b/SignalServiceKit/src/Messages/OWSSignalServiceProtos.pb.h
@@ -112,6 +112,7 @@ NSString *NSStringFromOWSSignalServiceProtosEnvelopeType(OWSSignalServiceProtosE
 typedef NS_ENUM(SInt32, OWSSignalServiceProtosDataMessageFlags) {
   OWSSignalServiceProtosDataMessageFlagsEndSession = 1,
   OWSSignalServiceProtosDataMessageFlagsExpirationTimerUpdate = 2,
+  OWSSignalServiceProtosDataMessageFlagsProfileKey = 4,
 };
 
 BOOL OWSSignalServiceProtosDataMessageFlagsIsValidValue(OWSSignalServiceProtosDataMessageFlags value);
diff --git a/SignalServiceKit/src/Messages/OWSSignalServiceProtos.pb.m b/SignalServiceKit/src/Messages/OWSSignalServiceProtos.pb.m
index b64ef57be..7c8c8c478 100644
--- a/SignalServiceKit/src/Messages/OWSSignalServiceProtos.pb.m
+++ b/SignalServiceKit/src/Messages/OWSSignalServiceProtos.pb.m
@@ -3103,6 +3103,7 @@ BOOL OWSSignalServiceProtosDataMessageFlagsIsValidValue(OWSSignalServiceProtosDa
   switch (value) {
     case OWSSignalServiceProtosDataMessageFlagsEndSession:
     case OWSSignalServiceProtosDataMessageFlagsExpirationTimerUpdate:
+    case OWSSignalServiceProtosDataMessageFlagsProfileKey:
       return YES;
     default:
       return NO;
@@ -3114,6 +3115,8 @@ NSString *NSStringFromOWSSignalServiceProtosDataMessageFlags(OWSSignalServicePro
       return @"OWSSignalServiceProtosDataMessageFlagsEndSession";
     case OWSSignalServiceProtosDataMessageFlagsExpirationTimerUpdate:
       return @"OWSSignalServiceProtosDataMessageFlagsExpirationTimerUpdate";
+    case OWSSignalServiceProtosDataMessageFlagsProfileKey:
+      return @"OWSSignalServiceProtosDataMessageFlagsProfileKey";
     default:
       return nil;
   }
diff --git a/SignalServiceKit/src/Protocols/ProtoBuf+OWS.h b/SignalServiceKit/src/Protocols/ProtoBuf+OWS.h
index 3ce1fc1d6..320635475 100644
--- a/SignalServiceKit/src/Protocols/ProtoBuf+OWS.h
+++ b/SignalServiceKit/src/Protocols/ProtoBuf+OWS.h
@@ -17,6 +17,7 @@ NS_ASSUME_NONNULL_BEGIN
 @interface OWSSignalServiceProtosDataMessageBuilder (OWS)
 
 - (void)addLocalProfileKeyIfNecessary:(TSThread *)thread recipientId:(NSString *_Nullable)recipientId;
+- (void)addLocalProfileKey;
 
 @end
 
diff --git a/SignalServiceKit/src/Protocols/ProtoBuf+OWS.m b/SignalServiceKit/src/Protocols/ProtoBuf+OWS.m
index a5afc5a45..00e207d9c 100644
--- a/SignalServiceKit/src/Protocols/ProtoBuf+OWS.m
+++ b/SignalServiceKit/src/Protocols/ProtoBuf+OWS.m
@@ -64,6 +64,11 @@ NS_ASSUME_NONNULL_BEGIN
     }
 }
 
+- (void)addLocalProfileKey
+{
+    [self setProfileKey:self.localProfileKey.keyData];
+}
+
 @end
 
 #pragma mark -