diff --git a/Postbox.xcodeproj/project.pbxproj b/Postbox.xcodeproj/project.pbxproj
index bdf7c30fc9..edbcdb9b82 100644
--- a/Postbox.xcodeproj/project.pbxproj
+++ b/Postbox.xcodeproj/project.pbxproj
@@ -55,6 +55,8 @@
 		D050F2681E4A5B5A00988324 /* TimestampBasedMessageAttributesIndexTable.swift in Sources */ = {isa = PBXBuildFile; fileRef = D0AAD1B01E3266B100D5B9DE /* TimestampBasedMessageAttributesIndexTable.swift */; };
 		D050F2691E4A5B5A00988324 /* MultiplePeersView.swift in Sources */ = {isa = PBXBuildFile; fileRef = D0BC386B1E3FCEE50044D6FE /* MultiplePeersView.swift */; };
 		D055BD331B7D3D2D00F06C0A /* MediaBox.swift in Sources */ = {isa = PBXBuildFile; fileRef = D055BD321B7D3D2D00F06C0A /* MediaBox.swift */; };
+		D0575AE31E9ECBB2006F2541 /* AccessChallengeDataView.swift in Sources */ = {isa = PBXBuildFile; fileRef = D0575AE21E9ECBB2006F2541 /* AccessChallengeDataView.swift */; };
+		D0575AE41E9ECBB2006F2541 /* AccessChallengeDataView.swift in Sources */ = {isa = PBXBuildFile; fileRef = D0575AE21E9ECBB2006F2541 /* AccessChallengeDataView.swift */; };
 		D05F09A61C9E9F9300BB6F96 /* MediaResourceStatus.swift in Sources */ = {isa = PBXBuildFile; fileRef = D05F09A51C9E9F9300BB6F96 /* MediaResourceStatus.swift */; };
 		D060B77B1CF4845A0050BE9B /* ReadStateTableTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = D060B77A1CF4845A0050BE9B /* ReadStateTableTests.swift */; };
 		D073CE741DCBF3B4007511FD /* Peer.swift in Sources */ = {isa = PBXBuildFile; fileRef = D0E3A7831B28AE0900A402D9 /* Peer.swift */; };
@@ -312,6 +314,7 @@
 		D044E1621B2AD677001EE087 /* MurMurHash32.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = MurMurHash32.m; sourceTree = "<group>"; };
 		D049EAEF1E44D9B900A2CD3A /* PostboxStateView.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = PostboxStateView.swift; sourceTree = "<group>"; };
 		D055BD321B7D3D2D00F06C0A /* MediaBox.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = MediaBox.swift; sourceTree = "<group>"; };
+		D0575AE21E9ECBB2006F2541 /* AccessChallengeDataView.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = AccessChallengeDataView.swift; sourceTree = "<group>"; };
 		D05F09A51C9E9F9300BB6F96 /* MediaResourceStatus.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = MediaResourceStatus.swift; sourceTree = "<group>"; };
 		D060B77A1CF4845A0050BE9B /* ReadStateTableTests.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = ReadStateTableTests.swift; sourceTree = "<group>"; };
 		D07516401B2D9CEF00AE42E0 /* sqlite3.c */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.c; path = sqlite3.c; sourceTree = "<group>"; };
@@ -654,6 +657,7 @@
 				D0FA0AC91E780A26005BB9B7 /* PostboxView.swift */,
 				D0FA0ACC1E781067005BB9B7 /* Views.swift */,
 				D0F53BF21E794C6700117362 /* PeerChatStateView.swift */,
+				D0575AE21E9ECBB2006F2541 /* AccessChallengeDataView.swift */,
 			);
 			name = Views;
 			sourceTree = "<group>";
@@ -910,6 +914,7 @@
 				C2A315BE1E2E733900D89000 /* PeerMergedOperationLogIndexTable.swift in Sources */,
 				C2A315BF1E2E733900D89000 /* PeerMergedOperationLogView.swift in Sources */,
 				C2A315BD1E2E732000D89000 /* PeerOperationLogMetadataTable.swift in Sources */,
+				D0575AE41E9ECBB2006F2541 /* AccessChallengeDataView.swift in Sources */,
 				C2A315BC1E2E730400D89000 /* PeerOperationLogTable.swift in Sources */,
 				C2AC9C131E1E5D200085C7DE /* UnreadMessageCountsView.swift in Sources */,
 				D0B418481D7DFE20004562A4 /* MessageHistoryView.swift in Sources */,
@@ -1033,6 +1038,7 @@
 				D07CFF831DCA909100761F81 /* PeerChatInterfaceStateTable.swift in Sources */,
 				D0F9E86F1C5A0E7600037222 /* KeychainTable.swift in Sources */,
 				D0E3A7821B28ADD000A402D9 /* Postbox.swift in Sources */,
+				D0575AE31E9ECBB2006F2541 /* AccessChallengeDataView.swift in Sources */,
 				D0E3A79E1B28B50400A402D9 /* Message.swift in Sources */,
 				D0C674C81CBB11C600183765 /* MessageHistoryReadStateTable.swift in Sources */,
 				D0DF0C8F1D81A350008AEB01 /* PeerView.swift in Sources */,
diff --git a/Postbox/AccessChallengeDataView.swift b/Postbox/AccessChallengeDataView.swift
new file mode 100644
index 0000000000..74913071ee
--- /dev/null
+++ b/Postbox/AccessChallengeDataView.swift
@@ -0,0 +1,34 @@
+import Foundation
+
+final class MutableAccessChallengeDataView: MutablePostboxView {
+    var data: PostboxAccessChallengeData
+    
+    init(postbox: Postbox) {
+        self.data = postbox.metadataTable.accessChallengeData()
+    }
+    
+    func replay(postbox: Postbox, transaction: PostboxTransaction) -> Bool {
+        var updated = false
+        
+        if let data = transaction.updatedAccessChallengeData {
+            if self.data != data {
+                self.data = data
+                updated = true
+            }
+        }
+        
+        return updated
+    }
+    
+    func immutableView() -> PostboxView {
+        return AccessChallengeDataView(self)
+    }
+}
+
+public final class AccessChallengeDataView: PostboxView {
+    public let data: PostboxAccessChallengeData
+    
+    init(_ view: MutableAccessChallengeDataView) {
+        self.data = view.data
+    }
+}
diff --git a/Postbox/AccountManager.swift b/Postbox/AccountManager.swift
index 7ab16482e0..43f62d3439 100644
--- a/Postbox/AccountManager.swift
+++ b/Postbox/AccountManager.swift
@@ -31,7 +31,7 @@ public final class AccountManager {
     fileprivate init(queue: Queue, basePath: String) {
         self.queue = queue
         self.basePath = basePath
-        let _ = try? FileManager.default.createDirectory(atPath: basePath, withIntermediateDirectories: false, attributes: nil)
+        let _ = try? FileManager.default.createDirectory(atPath: basePath, withIntermediateDirectories: true, attributes: nil)
         self.valueBox = SqliteValueBox(basePath: basePath + "/db", queue: queue)
         
         self.metadataTable = AccountManagerMetadataTable(valueBox: self.valueBox, table: AccountManagerMetadataTable.tableSpec(0))
diff --git a/Postbox/MediaBox.swift b/Postbox/MediaBox.swift
index 6616cdf65b..ef9ac03ffc 100644
--- a/Postbox/MediaBox.swift
+++ b/Postbox/MediaBox.swift
@@ -528,7 +528,7 @@ public final class MediaBox {
         }
     }
     
-    public func fetchedResource(_ resource: MediaResource, implNext:Bool = false) -> Signal<FetchResourceSourceType, NoError> {
+    public func fetchedResource(_ resource: MediaResource, implNext: Bool = false) -> Signal<FetchResourceSourceType, NoError> {
         return Signal { subscriber in
             let disposable = MetaDisposable()
             
diff --git a/Postbox/MetadataTable.swift b/Postbox/MetadataTable.swift
index 287ec88db6..50ec4da92c 100644
--- a/Postbox/MetadataTable.swift
+++ b/Postbox/MetadataTable.swift
@@ -8,19 +8,43 @@ private enum MetadataKey: Int32 {
     case AccessChallenge = 5
 }
 
+public struct AccessChallengeAttempts: Coding, Equatable {
+    public let count: Int32
+    public let timestamp: Int32
+    
+    public init(count: Int32, timestamp: Int32) {
+        self.count = count
+        self.timestamp = timestamp
+    }
+    
+    public init(decoder: Decoder) {
+        self.count = decoder.decodeInt32ForKey("c")
+        self.timestamp = decoder.decodeInt32ForKey("t")
+    }
+    
+    public func encode(_ encoder: Encoder) {
+        encoder.encodeInt32(self.count, forKey: "c")
+        encoder.encodeInt32(self.timestamp, forKey: "t")
+    }
+    
+    public static func ==(lhs: AccessChallengeAttempts, rhs: AccessChallengeAttempts) -> Bool {
+        return lhs.count == rhs.count && lhs.timestamp == rhs.timestamp
+    }
+}
+
 public enum PostboxAccessChallengeData: Coding, Equatable {
     case none
-    case numericalPassword(value: String, timeout: Int32?)
-    case plaintextPassword(value: String, timeout: Int32?)
+    case numericalPassword(value: String, timeout: Int32?, attempts: AccessChallengeAttempts?)
+    case plaintextPassword(value: String, timeout: Int32?, attempts: AccessChallengeAttempts?)
     
     public init(decoder: Decoder) {
         switch decoder.decodeInt32ForKey("r") as Int32 {
             case 0:
                 self = .none
             case 1:
-                self = .numericalPassword(value: decoder.decodeStringForKey("t"), timeout: decoder.decodeInt32ForKey("a"))
+                self = .numericalPassword(value: decoder.decodeStringForKey("t"), timeout: decoder.decodeInt32ForKey("a"), attempts: decoder.decodeObjectForKey("att", decoder: { AccessChallengeAttempts(decoder: $0) }) as? AccessChallengeAttempts)
             case 2:
-                self = .plaintextPassword(value: decoder.decodeStringForKey("t"), timeout: decoder.decodeInt32ForKey("a"))
+                self = .plaintextPassword(value: decoder.decodeStringForKey("t"), timeout: decoder.decodeInt32ForKey("a"), attempts: decoder.decodeObjectForKey("att", decoder: { AccessChallengeAttempts(decoder: $0) }) as? AccessChallengeAttempts)
             default:
                 assertionFailure()
                 self = .none
@@ -31,7 +55,7 @@ public enum PostboxAccessChallengeData: Coding, Equatable {
         switch self {
             case .none:
                 encoder.encodeInt32(0, forKey: "r")
-            case let .numericalPassword(text, timeout):
+            case let .numericalPassword(text, timeout, attempts):
                 encoder.encodeInt32(1, forKey: "r")
                 encoder.encodeString(text, forKey: "t")
                 if let timeout = timeout {
@@ -39,7 +63,12 @@ public enum PostboxAccessChallengeData: Coding, Equatable {
                 } else {
                     encoder.encodeNil(forKey: "a")
                 }
-            case let .plaintextPassword(text, timeout):
+                if let attempts = attempts {
+                    encoder.encodeObject(attempts, forKey: "att")
+                } else {
+                    encoder.encodeNil(forKey: "att")
+                }
+            case let .plaintextPassword(text, timeout, attempts):
                 encoder.encodeInt32(2, forKey: "r")
                 encoder.encodeString(text, forKey: "t")
                 if let timeout = timeout {
@@ -47,6 +76,11 @@ public enum PostboxAccessChallengeData: Coding, Equatable {
                 } else {
                     encoder.encodeNil(forKey: "a")
                 }
+                if let attempts = attempts {
+                    encoder.encodeObject(attempts, forKey: "att")
+                } else {
+                    encoder.encodeNil(forKey: "att")
+                }
         }
     }
     
@@ -58,20 +92,61 @@ public enum PostboxAccessChallengeData: Coding, Equatable {
                 } else {
                     return false
                 }
-            case let .numericalPassword(lhsText, lhsTimeout):
-                if case let .numericalPassword(rhsText, rhsTimeout) = rhs, lhsText == rhsText, lhsTimeout == rhsTimeout {
+            case let .numericalPassword(lhsText, lhsTimeout, lhsAttempts):
+                if case let .numericalPassword(rhsText, rhsTimeout, rhsAttempts) = rhs, lhsText == rhsText, lhsTimeout == rhsTimeout, lhsAttempts == rhsAttempts {
                     return true
                 } else {
                     return false
                 }
-            case let .plaintextPassword(lhsText, lhsTimeout):
-                if case let .plaintextPassword(rhsText, rhsTimeout) = rhs, lhsText == rhsText, lhsTimeout == rhsTimeout {
+            case let .plaintextPassword(lhsText, lhsTimeout, lhsAttempts):
+                if case let .plaintextPassword(rhsText, rhsTimeout, rhsAttempts) = rhs, lhsText == rhsText, lhsTimeout == rhsTimeout, lhsAttempts == rhsAttempts {
                     return true
                 } else {
                     return false
                 }
         }
     }
+    
+    public var isLockable: Bool {
+        if case .none = self {
+            return false
+        } else {
+            return true
+        }
+    }
+    
+    public var autolockDeadline: Int32? {
+        switch self {
+            case .none:
+                return nil
+            case let .numericalPassword(_, timeout, _):
+                return timeout
+            case let .plaintextPassword(_, timeout, _):
+                return timeout
+        }
+    }
+    
+    public var attempts: AccessChallengeAttempts? {
+        switch self {
+            case .none:
+                return nil
+            case let .numericalPassword(_, _, attempts):
+                return attempts
+            case let .plaintextPassword(_, _, attempts):
+                return attempts
+        }
+    }
+    
+    public func withUpdatedAutolockDeadline(_ autolockDeadline: Int32?) -> PostboxAccessChallengeData {
+        switch self {
+            case .none:
+                return self
+            case let .numericalPassword(value, _, attempts):
+                return .numericalPassword(value: value, timeout: autolockDeadline, attempts: attempts)
+            case let .plaintextPassword(value, _, attempts):
+                return .plaintextPassword(value: value, timeout: autolockDeadline, attempts: attempts)
+        }
+    }
 }
 
 final class MetadataTable: Table {
diff --git a/Postbox/Postbox.swift b/Postbox/Postbox.swift
index 27c2407288..8e7b6be3b6 100644
--- a/Postbox/Postbox.swift
+++ b/Postbox/Postbox.swift
@@ -535,7 +535,7 @@ public final class Modifier {
     
     public func setAccessChallengeData(_ data: PostboxAccessChallengeData) {
         assert(!self.disposed)
-        self.postbox?.metadataTable.setAccessChallengeData(data)
+        self.postbox?.setAccessChallengeData(data)
     }
 }
 
@@ -643,6 +643,7 @@ public final class Postbox {
     private var currentItemCollectionItemsOperations: [ItemCollectionId: [ItemCollectionItemsOperation]] = [:]
     private var currentItemCollectionInfosOperations: [ItemCollectionInfosOperation] = []
     private var currentUpdatedPeerChatStates = Set<PeerId>()
+    private var currentUpdatedAccessChallengeData: PostboxAccessChallengeData?
     
     private var currentReplaceChatListHoles: [(MessageIndex, ChatListHole?)] = []
     private var currentReplacedContactPeerIds: Set<PeerId>?
@@ -1251,7 +1252,7 @@ public final class Postbox {
             return self.peerTable.get(peerId)
         }, updatedTotalUnreadCount: &self.currentUpdatedTotalUnreadCount)
         
-        let transaction = PostboxTransaction(currentUpdatedState: self.currentUpdatedState, currentOperationsByPeerId: self.currentOperationsByPeerId, peerIdsWithFilledHoles: self.currentFilledHolesByPeerId, removedHolesByPeerId: self.currentRemovedHolesByPeerId, chatListOperations: chatListOperations, currentUpdatedPeers: self.currentUpdatedPeers, currentUpdatedPeerNotificationSettings: self.currentUpdatedPeerNotificationSettings, currentUpdatedCachedPeerData: self.currentUpdatedCachedPeerData, currentUpdatedPeerPresences: currentUpdatedPeerPresences, currentUpdatedPeerChatListEmbeddedStates: self.currentUpdatedPeerChatListEmbeddedStates, currentUpdatedTotalUnreadCount: self.currentUpdatedTotalUnreadCount, peerIdsWithUpdatedUnreadCounts: Set(transactionUnreadCountDeltas.keys), currentPeerMergedOperationLogOperations: self.currentPeerMergedOperationLogOperations, currentTimestampBasedMessageAttributesOperations: self.currentTimestampBasedMessageAttributesOperations, unsentMessageOperations: self.currentUnsentOperations, updatedSynchronizePeerReadStateOperations: self.currentUpdatedSynchronizeReadStateOperations, currentPreferencesOperations: self.currentPreferencesOperations, currentOrderedItemListOperations: self.currentOrderedItemListOperations, currentItemCollectionItemsOperations: self.currentItemCollectionItemsOperations, currentItemCollectionInfosOperations: self.currentItemCollectionInfosOperations, currentUpdatedPeerChatStates: self.currentUpdatedPeerChatStates, updatedMedia: self.currentUpdatedMedia, replaceContactPeerIds: self.currentReplacedContactPeerIds, currentUpdatedMasterClientId: currentUpdatedMasterClientId)
+        let transaction = PostboxTransaction(currentUpdatedState: self.currentUpdatedState, currentOperationsByPeerId: self.currentOperationsByPeerId, peerIdsWithFilledHoles: self.currentFilledHolesByPeerId, removedHolesByPeerId: self.currentRemovedHolesByPeerId, chatListOperations: chatListOperations, currentUpdatedPeers: self.currentUpdatedPeers, currentUpdatedPeerNotificationSettings: self.currentUpdatedPeerNotificationSettings, currentUpdatedCachedPeerData: self.currentUpdatedCachedPeerData, currentUpdatedPeerPresences: currentUpdatedPeerPresences, currentUpdatedPeerChatListEmbeddedStates: self.currentUpdatedPeerChatListEmbeddedStates, currentUpdatedTotalUnreadCount: self.currentUpdatedTotalUnreadCount, peerIdsWithUpdatedUnreadCounts: Set(transactionUnreadCountDeltas.keys), currentPeerMergedOperationLogOperations: self.currentPeerMergedOperationLogOperations, currentTimestampBasedMessageAttributesOperations: self.currentTimestampBasedMessageAttributesOperations, unsentMessageOperations: self.currentUnsentOperations, updatedSynchronizePeerReadStateOperations: self.currentUpdatedSynchronizeReadStateOperations, currentPreferencesOperations: self.currentPreferencesOperations, currentOrderedItemListOperations: self.currentOrderedItemListOperations, currentItemCollectionItemsOperations: self.currentItemCollectionItemsOperations, currentItemCollectionInfosOperations: self.currentItemCollectionInfosOperations, currentUpdatedPeerChatStates: self.currentUpdatedPeerChatStates, updatedAccessChallengeData: self.currentUpdatedAccessChallengeData, updatedMedia: self.currentUpdatedMedia, replaceContactPeerIds: self.currentReplacedContactPeerIds, currentUpdatedMasterClientId: currentUpdatedMasterClientId)
         var updatedTransactionState: Int64?
         var updatedMasterClientId: Int64?
         if !transaction.isEmpty {
@@ -1289,6 +1290,7 @@ public final class Postbox {
         self.currentItemCollectionItemsOperations.removeAll()
         self.currentItemCollectionInfosOperations.removeAll()
         self.currentUpdatedPeerChatStates.removeAll()
+        self.currentUpdatedAccessChallengeData = nil
         
         for table in self.tables {
             table.beforeCommit()
@@ -2036,9 +2038,7 @@ public final class Postbox {
     
     public func preferencesView(keys: [ValueBoxKey]) -> Signal<PreferencesView, NoError> {
         return self.modify { modifier -> Signal<PreferencesView, NoError> in
-            let view = MutablePreferencesView(keys: Set(keys), get: { key in
-                return self.preferencesTable.get(key: key)
-            })
+            let view = MutablePreferencesView(postbox: self, keys: Set(keys))
             let (index, signal) = self.viewTracker.addPreferencesView(view)
             
             return (.single(PreferencesView(view))
@@ -2094,6 +2094,11 @@ public final class Postbox {
         return self.orderedItemListTable.getItemIds(collectionId: collectionId)
     }
     
+    fileprivate func setAccessChallengeData(_ data: PostboxAccessChallengeData) {
+        self.currentUpdatedAccessChallengeData = data
+        self.metadataTable.setAccessChallengeData(data)
+    }
+    
     public func isMasterClient() -> Signal<Bool, NoError> {
         return self.modify { modifier -> Signal<Bool, NoError> in
             let sessionClientId = self.sessionClientId
diff --git a/Postbox/PostboxAccess.swift b/Postbox/PostboxAccess.swift
index eb2802f3fb..4e2d344e5e 100644
--- a/Postbox/PostboxAccess.swift
+++ b/Postbox/PostboxAccess.swift
@@ -38,7 +38,7 @@ public func accessPostbox(basePath: String, password: String?) -> Signal<Postbox
                 case .none:
                     subscriber.putNext(.unlocked)
                     subscriber.putCompletion()
-                case let .numericalPassword(text, _):
+                case let .numericalPassword(text, _, _):
                     if text == password {
                         subscriber.putNext(.unlocked)
                         subscriber.putCompletion()
@@ -46,7 +46,7 @@ public func accessPostbox(basePath: String, password: String?) -> Signal<Postbox
                         subscriber.putNext(.locked(.numericPassword(length: Int32(text.characters.count))))
                         subscriber.putCompletion()
                     }
-                case let .plaintextPassword(text, _):
+                case let .plaintextPassword(text, _, _):
                     if text == password {
                         subscriber.putNext(.unlocked)
                         subscriber.putCompletion()
diff --git a/Postbox/PostboxTransaction.swift b/Postbox/PostboxTransaction.swift
index 8c1e1e74df..fe70fbff78 100644
--- a/Postbox/PostboxTransaction.swift
+++ b/Postbox/PostboxTransaction.swift
@@ -20,6 +20,7 @@ final class PostboxTransaction {
     let currentItemCollectionItemsOperations: [ItemCollectionId: [ItemCollectionItemsOperation]]
     let currentItemCollectionInfosOperations: [ItemCollectionInfosOperation]
     let currentUpdatedPeerChatStates: Set<PeerId>
+    let updatedAccessChallengeData: PostboxAccessChallengeData?
     
     let unsentMessageOperations: [IntermediateMessageHistoryUnsentOperation]
     let updatedSynchronizePeerReadStateOperations: [PeerId: PeerReadStateSynchronizationOperation?]
@@ -100,10 +101,13 @@ final class PostboxTransaction {
         if !currentUpdatedPeerChatStates.isEmpty {
             return false
         }
+        if self.updatedAccessChallengeData != nil {
+            return false
+        }
         return true
     }
     
-    init(currentUpdatedState: Coding?, currentOperationsByPeerId: [PeerId: [MessageHistoryOperation]], peerIdsWithFilledHoles: [PeerId: [MessageIndex: HoleFillDirection]], removedHolesByPeerId: [PeerId: [MessageIndex: HoleFillDirection]], chatListOperations: [ChatListOperation], currentUpdatedPeers: [PeerId: Peer], currentUpdatedPeerNotificationSettings: [PeerId: PeerNotificationSettings], currentUpdatedCachedPeerData: [PeerId: CachedPeerData], currentUpdatedPeerPresences: [PeerId: PeerPresence], currentUpdatedPeerChatListEmbeddedStates: [PeerId: PeerChatListEmbeddedInterfaceState?], currentUpdatedTotalUnreadCount: Int32?, peerIdsWithUpdatedUnreadCounts: Set<PeerId>, currentPeerMergedOperationLogOperations: [PeerMergedOperationLogOperation], currentTimestampBasedMessageAttributesOperations: [TimestampBasedMessageAttributesOperation], unsentMessageOperations: [IntermediateMessageHistoryUnsentOperation], updatedSynchronizePeerReadStateOperations: [PeerId: PeerReadStateSynchronizationOperation?], currentPreferencesOperations: [PreferencesOperation], currentOrderedItemListOperations: [Int32: [OrderedItemListOperation]], currentItemCollectionItemsOperations: [ItemCollectionId: [ItemCollectionItemsOperation]], currentItemCollectionInfosOperations: [ItemCollectionInfosOperation], currentUpdatedPeerChatStates: Set<PeerId>, updatedMedia: [MediaId: Media?], replaceContactPeerIds: Set<PeerId>?, currentUpdatedMasterClientId: Int64?) {
+    init(currentUpdatedState: Coding?, currentOperationsByPeerId: [PeerId: [MessageHistoryOperation]], peerIdsWithFilledHoles: [PeerId: [MessageIndex: HoleFillDirection]], removedHolesByPeerId: [PeerId: [MessageIndex: HoleFillDirection]], chatListOperations: [ChatListOperation], currentUpdatedPeers: [PeerId: Peer], currentUpdatedPeerNotificationSettings: [PeerId: PeerNotificationSettings], currentUpdatedCachedPeerData: [PeerId: CachedPeerData], currentUpdatedPeerPresences: [PeerId: PeerPresence], currentUpdatedPeerChatListEmbeddedStates: [PeerId: PeerChatListEmbeddedInterfaceState?], currentUpdatedTotalUnreadCount: Int32?, peerIdsWithUpdatedUnreadCounts: Set<PeerId>, currentPeerMergedOperationLogOperations: [PeerMergedOperationLogOperation], currentTimestampBasedMessageAttributesOperations: [TimestampBasedMessageAttributesOperation], unsentMessageOperations: [IntermediateMessageHistoryUnsentOperation], updatedSynchronizePeerReadStateOperations: [PeerId: PeerReadStateSynchronizationOperation?], currentPreferencesOperations: [PreferencesOperation], currentOrderedItemListOperations: [Int32: [OrderedItemListOperation]], currentItemCollectionItemsOperations: [ItemCollectionId: [ItemCollectionItemsOperation]], currentItemCollectionInfosOperations: [ItemCollectionInfosOperation], currentUpdatedPeerChatStates: Set<PeerId>, updatedAccessChallengeData: PostboxAccessChallengeData?, updatedMedia: [MediaId: Media?], replaceContactPeerIds: Set<PeerId>?, currentUpdatedMasterClientId: Int64?) {
         self.currentUpdatedState = currentUpdatedState
         self.currentOperationsByPeerId = currentOperationsByPeerId
         self.peerIdsWithFilledHoles = peerIdsWithFilledHoles
@@ -125,6 +129,7 @@ final class PostboxTransaction {
         self.currentItemCollectionItemsOperations = currentItemCollectionItemsOperations
         self.currentItemCollectionInfosOperations = currentItemCollectionInfosOperations
         self.currentUpdatedPeerChatStates = currentUpdatedPeerChatStates
+        self.updatedAccessChallengeData = updatedAccessChallengeData
         self.updatedMedia = updatedMedia
         self.replaceContactPeerIds = replaceContactPeerIds
         self.currentUpdatedMasterClientId = currentUpdatedMasterClientId
diff --git a/Postbox/PreferencesView.swift b/Postbox/PreferencesView.swift
index bdc6195672..4a7b809e03 100644
--- a/Postbox/PreferencesView.swift
+++ b/Postbox/PreferencesView.swift
@@ -1,23 +1,23 @@
 import Foundation
 
-final class MutablePreferencesView {
+final class MutablePreferencesView: MutablePostboxView {
     fileprivate let keys: Set<ValueBoxKey>
     fileprivate var values: [ValueBoxKey: PreferencesEntry]
     
-    init(keys: Set<ValueBoxKey>, get: (ValueBoxKey) -> PreferencesEntry?) {
+    init(postbox: Postbox, keys: Set<ValueBoxKey>) {
         self.keys = keys
         var values: [ValueBoxKey: PreferencesEntry] = [:]
         for key in keys {
-            if let value = get(key) {
+            if let value = postbox.preferencesTable.get(key: key) {
                 values[key] = value
             }
         }
         self.values = values
     }
     
-    func replay(operations: [PreferencesOperation], get: (ValueBoxKey) -> PreferencesEntry?) -> Bool {
+    func replay(postbox: Postbox, transaction: PostboxTransaction) -> Bool {
         var updated = false
-        for operation in operations {
+        for operation in transaction.currentPreferencesOperations {
             switch operation {
                 case let .update(key, value):
                     if self.keys.contains(key) {
@@ -44,9 +44,13 @@ final class MutablePreferencesView {
         
         return updated
     }
+    
+    func immutableView() -> PostboxView {
+        return PreferencesView(self)
+    }
 }
 
-public final class PreferencesView {
+public final class PreferencesView: PostboxView {
     public let values: [ValueBoxKey: PreferencesEntry]
     
     init(_ view: MutablePreferencesView) {
diff --git a/Postbox/ViewTracker.swift b/Postbox/ViewTracker.swift
index 7495e4cc4f..b5f4ca9d38 100644
--- a/Postbox/ViewTracker.swift
+++ b/Postbox/ViewTracker.swift
@@ -501,7 +501,7 @@ final class ViewTracker {
         }
         
         for (mutableView, pipe) in self.preferencesViews.copyItems() {
-            if mutableView.replay(operations: transaction.currentPreferencesOperations, get: self.getPreferencesEntry) {
+            if mutableView.replay(postbox: postbox, transaction: transaction) {
                 pipe.putNext(PreferencesView(mutableView))
             }
         }
diff --git a/Postbox/Views.swift b/Postbox/Views.swift
index c0ccb6b3b1..43fa9950df 100644
--- a/Postbox/Views.swift
+++ b/Postbox/Views.swift
@@ -6,6 +6,8 @@ public enum PostboxViewKey: Hashable {
     case itemCollectionInfo(id: ItemCollectionId)
     case peerChatState(peerId: PeerId)
     case orderedItemList(id: Int32)
+    case accessChallengeData
+    case preferences(keys: Set<ValueBoxKey>)
     
     public var hashValue: Int {
         switch self {
@@ -19,6 +21,10 @@ public enum PostboxViewKey: Hashable {
                 return id.hashValue
             case let .orderedItemList(id):
                 return id.hashValue
+            case .accessChallengeData:
+                return 2
+            case .preferences:
+                return 3
         }
     }
     
@@ -54,6 +60,18 @@ public enum PostboxViewKey: Hashable {
                 } else {
                     return false
                 }
+            case .accessChallengeData:
+                if case .accessChallengeData = rhs {
+                    return true
+                } else {
+                    return false
+                }
+            case let .preferences(lhsKeys):
+                if case let .preferences(rhsKeys) = rhs, lhsKeys == rhsKeys {
+                    return true
+                } else {
+                    return false
+                }
         }
     }
 }
@@ -70,5 +88,9 @@ func postboxViewForKey(postbox: Postbox, key: PostboxViewKey) -> MutablePostboxV
             return MutablePeerChatStateView(postbox: postbox, peerId: peerId)
         case let .orderedItemList(id):
             return MutableOrderedItemListView(postbox: postbox, collectionId: id)
+        case .accessChallengeData:
+            return MutableAccessChallengeDataView(postbox: postbox)
+        case let .preferences(keys):
+            return MutablePreferencesView(postbox: postbox, keys: keys)
     }
 }