diff --git a/app/src/main/AndroidManifest.xml b/app/src/main/AndroidManifest.xml
index 0613db3eb..79fa6bea8 100644
--- a/app/src/main/AndroidManifest.xml
+++ b/app/src/main/AndroidManifest.xml
@@ -20,6 +20,7 @@
         android:allowBackup="true"
         android:fullBackupContent="@xml/backup"
         android:backupAgent="com.kunzisoft.keepass.backup.SettingsBackupAgent"
+        android:largeHeap="true"
         android:theme="@style/KeepassDXStyle.Night">
         <!-- TODO backup API Key -->
         <meta-data
diff --git a/app/src/main/java/com/kunzisoft/keepass/database/element/PwDatabaseV4.kt b/app/src/main/java/com/kunzisoft/keepass/database/element/PwDatabaseV4.kt
index 361297145..8fad32a6c 100644
--- a/app/src/main/java/com/kunzisoft/keepass/database/element/PwDatabaseV4.kt
+++ b/app/src/main/java/com/kunzisoft/keepass/database/element/PwDatabaseV4.kt
@@ -31,6 +31,8 @@ import com.kunzisoft.keepass.crypto.keyDerivation.KdfFactory
 import com.kunzisoft.keepass.crypto.keyDerivation.KdfParameters
 import com.kunzisoft.keepass.database.element.PwDatabaseV3.Companion.BACKUP_FOLDER_TITLE
 import com.kunzisoft.keepass.database.exception.UnknownKDF
+import com.kunzisoft.keepass.database.file.PwDbHeaderV4.Companion.FILE_VERSION_32_3
+import com.kunzisoft.keepass.database.file.PwDbHeaderV4.Companion.FILE_VERSION_32_4
 import com.kunzisoft.keepass.utils.VariantDictionary
 import org.w3c.dom.Node
 import org.w3c.dom.Text
@@ -56,6 +58,7 @@ class PwDatabaseV4 : PwDatabase<UUID, UUID, PwGroupV4, PwEntryV4> {
     private var numKeyEncRounds: Long = 0
     var publicCustomData = VariantDictionary()
 
+    var kdbxVersion: Long = 0
     var name = ""
     var nameChanged = PwDate()
     // TODO change setting date
@@ -116,7 +119,14 @@ class PwDatabaseV4 : PwDatabase<UUID, UUID, PwGroupV4, PwEntryV4> {
     }
 
     override val version: String
-        get() = "KeePass 2"
+        get() {
+            val kdbxStringVersion = when(kdbxVersion) {
+                FILE_VERSION_32_3 -> "3.1"
+                FILE_VERSION_32_4 -> "4.0"
+                else -> "UNKNOWN"
+            }
+            return "KeePass 2 - KDBX$kdbxStringVersion"
+        }
 
     override val kdfEngine: KdfEngine?
         get() = try {
diff --git a/app/src/main/java/com/kunzisoft/keepass/database/element/PwEntryV4.kt b/app/src/main/java/com/kunzisoft/keepass/database/element/PwEntryV4.kt
index f4c39930e..cfb5510e5 100644
--- a/app/src/main/java/com/kunzisoft/keepass/database/element/PwEntryV4.kt
+++ b/app/src/main/java/com/kunzisoft/keepass/database/element/PwEntryV4.kt
@@ -49,7 +49,7 @@ class PwEntryV4 : PwEntry<UUID, UUID, PwGroupV4, PwEntryV4>, PwNodeV4Interface {
     var iconCustom = PwIconCustom.UNKNOWN_ICON
     private var customData = HashMap<String, String>()
     var fields = HashMap<String, ProtectedString>()
-    val binaries = HashMap<String, ProtectedBinary>()
+    var binaries = HashMap<String, ProtectedBinary>()
     var foregroundColor = ""
     var backgroundColor = ""
     var overrideURL = ""
@@ -98,7 +98,7 @@ class PwEntryV4 : PwEntry<UUID, UUID, PwGroupV4, PwEntryV4>, PwNodeV4Interface {
         locationChanged = parcel.readParcelable(PwDate::class.java.classLoader) ?: locationChanged
         customData = ParcelableUtil.readStringParcelableMap(parcel)
         fields = ParcelableUtil.readStringParcelableMap(parcel, ProtectedString::class.java)
-        // TODO binaries = ParcelableUtil.readStringParcelableMap(parcel, ProtectedBinary.class);
+        binaries = ParcelableUtil.readStringParcelableMap(parcel, ProtectedBinary::class.java)
         foregroundColor = parcel.readString() ?: foregroundColor
         backgroundColor = parcel.readString() ?: backgroundColor
         overrideURL = parcel.readString() ?: overrideURL
@@ -116,7 +116,7 @@ class PwEntryV4 : PwEntry<UUID, UUID, PwGroupV4, PwEntryV4>, PwNodeV4Interface {
         dest.writeParcelable(locationChanged, flags)
         ParcelableUtil.writeStringParcelableMap(dest, customData)
         ParcelableUtil.writeStringParcelableMap(dest, flags, fields)
-        // TODO ParcelableUtil.writeStringParcelableMap(dest, flags, binaries);
+        ParcelableUtil.writeStringParcelableMap(dest, flags, binaries)
         dest.writeString(foregroundColor)
         dest.writeString(backgroundColor)
         dest.writeString(overrideURL)
diff --git a/app/src/main/java/com/kunzisoft/keepass/database/element/security/ProtectedBinary.kt b/app/src/main/java/com/kunzisoft/keepass/database/element/security/ProtectedBinary.kt
index 02ba53f6d..584a68400 100644
--- a/app/src/main/java/com/kunzisoft/keepass/database/element/security/ProtectedBinary.kt
+++ b/app/src/main/java/com/kunzisoft/keepass/database/element/security/ProtectedBinary.kt
@@ -22,18 +22,14 @@ package com.kunzisoft.keepass.database.element.security
 import android.os.Parcel
 import android.os.Parcelable
 import android.util.Log
+import java.io.*
 
-import java.io.ByteArrayInputStream
-import java.io.File
-import java.io.FileInputStream
-import java.io.IOException
-import java.io.InputStream
 import java.util.Arrays
 
 class ProtectedBinary : Parcelable {
 
+    var isCompressed: Boolean? = null // Only for KDBX3.1-
     var isProtected: Boolean = false
-        private set
     private var data: ByteArray? = null
     private var dataFile: File? = null
 
@@ -49,30 +45,36 @@ class ProtectedBinary : Parcelable {
      * Empty protected binary
      */
     constructor() {
+        this.isCompressed = null
         this.isProtected = false
         this.data = null
         this.dataFile = null
     }
 
     constructor(protectedBinary: ProtectedBinary) {
+        this.isCompressed = protectedBinary.isCompressed
         this.isProtected = protectedBinary.isProtected
         this.data = protectedBinary.data
         this.dataFile = protectedBinary.dataFile
     }
 
-    constructor(enableProtection: Boolean, data: ByteArray?) {
+    constructor(data: ByteArray?, enableProtection: Boolean = false, compressed: Boolean? = null) {
+        this.isCompressed = compressed
         this.isProtected = enableProtection
         this.data = data
         this.dataFile = null
     }
 
-    constructor(enableProtection: Boolean, dataFile: File) {
+    constructor(dataFile: File, enableProtection: Boolean = false, compressed: Boolean? = null) {
+        this.isCompressed = compressed
         this.isProtected = enableProtection
         this.data = null
         this.dataFile = dataFile
     }
 
     private constructor(parcel: Parcel) {
+        val compressedByte = parcel.readByte().toInt()
+        isCompressed = if (compressedByte == 2) null else compressedByte != 0
         isProtected = parcel.readByte().toInt() != 0
         data = ByteArray(parcel.readInt())
         parcel.readByteArray(data)
@@ -80,11 +82,11 @@ class ProtectedBinary : Parcelable {
     }
 
     @Throws(IOException::class)
-    fun getData(): InputStream? {
+    fun getInputDataStream(): InputStream {
         return when {
             data != null -> ByteArrayInputStream(data)
             dataFile != null -> FileInputStream(dataFile!!)
-            else -> null
+            else -> throw IOException("Unable to get binary data")
         }
     }
 
@@ -111,12 +113,15 @@ class ProtectedBinary : Parcelable {
                 && dataFile == null && other.dataFile == null)
             sameData = true
 
-        return isProtected == other.isProtected && sameData
+        return isCompressed == other.isCompressed
+                && isProtected == other.isProtected
+                && sameData
     }
 
     override fun hashCode(): Int {
 
         var result = 0
+        result = 31 * result + if (isCompressed == null) 2 else if (isCompressed!!) 1 else 0
         result = 31 * result + if (isProtected) 1 else 0
         result = 31 * result + dataFile!!.hashCode()
         result = 31 * result + Arrays.hashCode(data)
@@ -128,6 +133,7 @@ class ProtectedBinary : Parcelable {
     }
 
     override fun writeToParcel(dest: Parcel, flags: Int) {
+        dest.writeByte((if (isCompressed == null) 2 else if (isCompressed!!) 1 else 0).toByte())
         dest.writeByte((if (isProtected) 1 else 0).toByte())
         dest.writeInt(data?.size ?: 0)
         dest.writeByteArray(data)
diff --git a/app/src/main/java/com/kunzisoft/keepass/database/file/load/ImporterV4.kt b/app/src/main/java/com/kunzisoft/keepass/database/file/load/ImporterV4.kt
index dd9f8838e..25a406e0c 100644
--- a/app/src/main/java/com/kunzisoft/keepass/database/file/load/ImporterV4.kt
+++ b/app/src/main/java/com/kunzisoft/keepass/database/file/load/ImporterV4.kt
@@ -32,13 +32,9 @@ import com.kunzisoft.keepass.database.element.security.ProtectedString
 import com.kunzisoft.keepass.database.exception.*
 import com.kunzisoft.keepass.database.file.KDBX4DateUtil
 import com.kunzisoft.keepass.database.file.PwDbHeaderV4
-import com.kunzisoft.keepass.stream.BetterCipherInputStream
-import com.kunzisoft.keepass.stream.HashedBlockInputStream
-import com.kunzisoft.keepass.stream.HmacBlockInputStream
-import com.kunzisoft.keepass.stream.LEDataInputStream
+import com.kunzisoft.keepass.stream.*
 import com.kunzisoft.keepass.tasks.ProgressTaskUpdater
 import com.kunzisoft.keepass.utils.DatabaseInputOutputUtils
-import org.apache.commons.io.IOUtils
 import org.spongycastle.crypto.StreamCipher
 import org.xmlpull.v1.XmlPullParser
 import org.xmlpull.v1.XmlPullParserException
@@ -58,7 +54,6 @@ class ImporterV4(private val streamDir: File,
     private lateinit var mDatabase: PwDatabaseV4
 
     private var hashOfHeader: ByteArray? = null
-    private var version: Long = 0
 
     private val unusedCacheFileName: String
         get() = mDatabase.binPool.findUnusedKey().toString()
@@ -102,7 +97,7 @@ class ImporterV4(private val streamDir: File,
             val header = PwDbHeaderV4(mDatabase)
 
             val headerAndHash = header.loadFromFile(databaseInputStream)
-            version = header.version
+            mDatabase.kdbxVersion = header.version
 
             hashOfHeader = headerAndHash.hash
             val pbHeader = headerAndHash.header
@@ -124,7 +119,7 @@ class ImporterV4(private val streamDir: File,
             }
 
             val isPlain: InputStream
-            if (version < PwDbHeaderV4.FILE_VERSION_32_4) {
+            if (mDatabase.kdbxVersion < PwDbHeaderV4.FILE_VERSION_32_4) {
 
                 val decrypted = attachCipherStream(databaseInputStream, cipher)
                 val dataDecrypted = LEDataInputStream(decrypted)
@@ -172,7 +167,7 @@ class ImporterV4(private val streamDir: File,
                 else -> isPlain
             }
 
-            if (version >= PwDbHeaderV4.FILE_VERSION_32_4) {
+            if (mDatabase.kdbxVersion >= PwDbHeaderV4.FILE_VERSION_32_4) {
                 loadInnerHeader(inputStreamXml, header)
             }
 
@@ -241,9 +236,13 @@ class ImporterV4(private val streamDir: File,
                 // Read in a file
                 val file = File(streamDir, unusedCacheFileName)
                 FileOutputStream(file).use { outputStream ->
-                    dataInputStream.readBytes(byteLength) { outputStream.write(it) }
+                    dataInputStream.readBytes(byteLength, object : ReadBytes {
+                        override fun read(buffer: ByteArray) {
+                            outputStream.write(buffer)
+                        }
+                    })
                 }
-                val protectedBinary = ProtectedBinary(protectedFlag, file)
+                val protectedBinary = ProtectedBinary(file, protectedFlag)
                 mDatabase.binPool.add(protectedBinary)
             }
             else -> {
@@ -432,7 +431,7 @@ class ImporterV4(private val streamDir: File,
             KdbContext.Binaries -> if (name.equals(PwDatabaseV4XML.ElemBinary, ignoreCase = true)) {
                 val key = xpp.getAttributeValue(null, PwDatabaseV4XML.AttrId)
                 if (key != null) {
-                    val pbData = readProtectedBinary(xpp)
+                    val pbData = readBinary(xpp)
                     val id = Integer.parseInt(key)
                     mDatabase.binPool.put(id, pbData!!)
                 } else {
@@ -606,7 +605,7 @@ class ImporterV4(private val streamDir: File,
             KdbContext.EntryBinary -> if (name.equals(PwDatabaseV4XML.ElemKey, ignoreCase = true)) {
                 ctxBinaryName = readString(xpp)
             } else if (name.equals(PwDatabaseV4XML.ElemValue, ignoreCase = true)) {
-                ctxBinaryValue = readProtectedBinary(xpp)
+                ctxBinaryValue = readBinary(xpp)
             }
 
             KdbContext.EntryAutoType -> if (name.equals(PwDatabaseV4XML.ElemAutoTypeEnabled, ignoreCase = true)) {
@@ -806,7 +805,7 @@ class ImporterV4(private val streamDir: File,
         val sDate = readString(xpp)
         var utcDate: Date? = null
 
-        if (version >= PwDbHeaderV4.FILE_VERSION_32_4) {
+        if (mDatabase.kdbxVersion >= PwDbHeaderV4.FILE_VERSION_32_4) {
             var buf = Base64.decode(sDate, BASE_64_FLAG)
             if (buf.size != 8) {
                 val buf8 = ByteArray(8)
@@ -939,7 +938,9 @@ class ImporterV4(private val streamDir: File,
     }
 
     @Throws(XmlPullParserException::class, IOException::class)
-    private fun readProtectedBinary(xpp: XmlPullParser): ProtectedBinary? {
+    private fun readBinary(xpp: XmlPullParser): ProtectedBinary? {
+
+        // Reference Id to a binary already present in binary pool
         val ref = xpp.getAttributeValue(null, PwDatabaseV4XML.AttrRef)
         if (ref != null) {
             xpp.next() // Consume end tag
@@ -948,41 +949,38 @@ class ImporterV4(private val streamDir: File,
             return mDatabase.binPool[id]
         }
 
-        var compressed = false
-        var protected = false
+        // New binary to retrieve
+        else {
+            var compressed: Boolean? = null
+            var protected = false
 
-        if (xpp.attributeCount > 0) {
-            val compress = xpp.getAttributeValue(null, PwDatabaseV4XML.AttrCompressed)
-            if (compress != null) {
-                compressed = compress.equals(PwDatabaseV4XML.ValTrue, ignoreCase = true)
-            }
-
-            val protect = xpp.getAttributeValue(null, PwDatabaseV4XML.AttrProtected)
-            if (protect != null) {
-                protected = protect.equals(PwDatabaseV4XML.ValTrue, ignoreCase = true)
-            }
-        }
-
-        val base64 = readString(xpp)
-        if (base64.isEmpty())
-            return ProtectedBinary()
-        val data = Base64.decode(base64, BASE_64_FLAG)
-
-        return if (!compressed && data.size <= BUFFER_SIZE_BYTES) {
-            // Small data, don't need a file
-            ProtectedBinary(protected, data)
-        } else {
-            val file = File(streamDir, unusedCacheFileName)
-            if (compressed) {
-                FileOutputStream(file).use { outputStream ->
-                    IOUtils.copy(GZIPInputStream(ByteArrayInputStream(data)), outputStream)
+            if (xpp.attributeCount > 0) {
+                val compress = xpp.getAttributeValue(null, PwDatabaseV4XML.AttrCompressed)
+                if (compress != null) {
+                    compressed = compress.equals(PwDatabaseV4XML.ValTrue, ignoreCase = true)
                 }
+
+                val protect = xpp.getAttributeValue(null, PwDatabaseV4XML.AttrProtected)
+                if (protect != null) {
+                    protected = protect.equals(PwDatabaseV4XML.ValTrue, ignoreCase = true)
+                }
+            }
+
+            val base64 = readString(xpp)
+            if (base64.isEmpty())
+                return ProtectedBinary()
+            val data = Base64.decode(base64, BASE_64_FLAG)
+
+            return if (data.size <= BUFFER_SIZE_BYTES) {
+                // Small data, don't need a file
+                ProtectedBinary(data, protected, compressed)
             } else {
+                val file = File(streamDir, unusedCacheFileName)
                 FileOutputStream(file).use { outputStream ->
                     outputStream.write(data)
                 }
+                ProtectedBinary(file, protected, compressed)
             }
-            ProtectedBinary(protected, file)
         }
     }
 
diff --git a/app/src/main/java/com/kunzisoft/keepass/database/file/save/PwDbInnerHeaderOutputV4.kt b/app/src/main/java/com/kunzisoft/keepass/database/file/save/PwDbInnerHeaderOutputV4.kt
index 70868ba5e..9705a2736 100644
--- a/app/src/main/java/com/kunzisoft/keepass/database/file/save/PwDbInnerHeaderOutputV4.kt
+++ b/app/src/main/java/com/kunzisoft/keepass/database/file/save/PwDbInnerHeaderOutputV4.kt
@@ -22,10 +22,10 @@ package com.kunzisoft.keepass.database.file.save
 import com.kunzisoft.keepass.database.element.PwDatabaseV4
 import com.kunzisoft.keepass.database.element.PwDatabaseV4.Companion.BUFFER_SIZE_BYTES
 import com.kunzisoft.keepass.database.file.PwDbHeaderV4
-import com.kunzisoft.keepass.stream.ActionReadBytes
+import com.kunzisoft.keepass.stream.ReadBytes
 import com.kunzisoft.keepass.stream.LEDataOutputStream
+import com.kunzisoft.keepass.stream.readFromStream
 import java.io.IOException
-import java.io.InputStream
 import java.io.OutputStream
 import kotlin.experimental.or
 
@@ -58,32 +58,16 @@ class PwDbInnerHeaderOutputV4(private val database: PwDatabaseV4,
             dataOutputStream.writeInt(protectedBinary.length().toInt() + 1) // TODO verify
             dataOutputStream.write(flag.toInt())
 
-            protectedBinary.getData()?.let {
-                readBytes(it, ActionReadBytes { buffer ->
-                    dataOutputStream.write(buffer)
-                })
-            } ?: throw IOException("Can't write protected binary")
+            readFromStream(protectedBinary.getInputDataStream(), BUFFER_SIZE_BYTES,
+                object : ReadBytes {
+                    override fun read(buffer: ByteArray) {
+                        dataOutputStream.write(buffer)
+                    }
+                }
+            )
         }
 
         dataOutputStream.write(PwDbHeaderV4.PwDbInnerHeaderV4Fields.EndOfHeader.toInt())
         dataOutputStream.writeInt(0)
     }
-
-    @Throws(IOException::class)
-    fun readBytes(inputStream: InputStream, actionReadBytes: ActionReadBytes) {
-        val buffer = ByteArray(BUFFER_SIZE_BYTES)
-        var read = 0
-        while (read != -1) {
-            read = inputStream.read(buffer, 0, buffer.size)
-            if (read != -1) {
-                val optimizedBuffer: ByteArray = if (buffer.size == read) {
-                    buffer
-                } else {
-                    buffer.copyOf(read)
-                }
-                actionReadBytes.doAction(optimizedBuffer)
-            }
-        }
-    }
-
 }
diff --git a/app/src/main/java/com/kunzisoft/keepass/database/file/save/PwDbV4Output.kt b/app/src/main/java/com/kunzisoft/keepass/database/file/save/PwDbV4Output.kt
index 49496d2f4..f039c2a45 100644
--- a/app/src/main/java/com/kunzisoft/keepass/database/file/save/PwDbV4Output.kt
+++ b/app/src/main/java/com/kunzisoft/keepass/database/file/save/PwDbV4Output.kt
@@ -37,9 +37,7 @@ import com.kunzisoft.keepass.database.exception.DatabaseOutputException
 import com.kunzisoft.keepass.database.exception.UnknownKDF
 import com.kunzisoft.keepass.database.file.KDBX4DateUtil
 import com.kunzisoft.keepass.database.file.PwDbHeaderV4
-import com.kunzisoft.keepass.stream.HashedBlockOutputStream
-import com.kunzisoft.keepass.stream.HmacBlockOutputStream
-import com.kunzisoft.keepass.stream.LEDataOutputStream
+import com.kunzisoft.keepass.stream.*
 import com.kunzisoft.keepass.utils.DatabaseInputOutputUtils
 import org.joda.time.DateTime
 import org.spongycastle.crypto.StreamCipher
@@ -53,7 +51,8 @@ import javax.crypto.Cipher
 import javax.crypto.CipherOutputStream
 
 
-class PwDbV4Output(private val mDatabaseV4: PwDatabaseV4, outputStream: OutputStream) : PwDbOutput<PwDbHeaderV4>(outputStream) {
+class PwDbV4Output(private val mDatabaseV4: PwDatabaseV4,
+                   outputStream: OutputStream) : PwDbOutput<PwDbHeaderV4>(outputStream) {
 
     private var randomStream: StreamCipher? = null
     private lateinit var xml: XmlSerializer
@@ -75,17 +74,16 @@ class PwDbV4Output(private val mDatabaseV4: PwDatabaseV4, outputStream: OutputSt
             header = outputHeader(mOS)
 
             val osPlain: OutputStream
-            if (header!!.version < PwDbHeaderV4.FILE_VERSION_32_4) {
+            osPlain = if (header!!.version < PwDbHeaderV4.FILE_VERSION_32_4) {
                 val cos = attachStreamEncryptor(header!!, mOS)
                 cos.write(header!!.streamStartBytes)
 
-                osPlain = HashedBlockOutputStream(cos)
+                HashedBlockOutputStream(cos)
             } else {
                 mOS.write(hashOfHeader!!)
                 mOS.write(headerHmac!!)
 
-                val hbos = HmacBlockOutputStream(mOS, mDatabaseV4.hmacKey)
-                osPlain = attachStreamEncryptor(header!!, hbos)
+                attachStreamEncryptor(header!!, HmacBlockOutputStream(mOS, mDatabaseV4.hmacKey))
             }
 
             val osXml: OutputStream
@@ -114,11 +112,11 @@ class PwDbV4Output(private val mDatabaseV4: PwDatabaseV4, outputStream: OutputSt
     }
 
     @Throws(IllegalArgumentException::class, IllegalStateException::class, IOException::class)
-    private fun outputDatabase(os: OutputStream) {
+    private fun outputDatabase(outputStream: OutputStream) {
 
         xml = Xml.newSerializer()
 
-        xml.setOutput(os, "UTF-8")
+        xml.setOutput(outputStream, "UTF-8")
         xml.startDocument("UTF-8", true)
 
         xml.startTag(null, PwDatabaseV4XML.ElemDocNode)
@@ -210,17 +208,17 @@ class PwDbV4Output(private val mDatabaseV4: PwDatabaseV4, outputStream: OutputSt
         writeCustomIconList()
 
         writeObject(PwDatabaseV4XML.ElemRecycleBinEnabled, mDatabaseV4.isRecycleBinEnabled)
-        writeObject(PwDatabaseV4XML.ElemRecycleBinUuid, mDatabaseV4.recycleBinUUID)
+        writeUuid(PwDatabaseV4XML.ElemRecycleBinUuid, mDatabaseV4.recycleBinUUID)
         writeObject(PwDatabaseV4XML.ElemRecycleBinChanged, mDatabaseV4.recycleBinChanged)
-        writeObject(PwDatabaseV4XML.ElemEntryTemplatesGroup, mDatabaseV4.entryTemplatesGroup)
+        writeUuid(PwDatabaseV4XML.ElemEntryTemplatesGroup, mDatabaseV4.entryTemplatesGroup)
         writeObject(PwDatabaseV4XML.ElemEntryTemplatesGroupChanged, mDatabaseV4.entryTemplatesGroupChanged.date)
         writeObject(PwDatabaseV4XML.ElemHistoryMaxItems, mDatabaseV4.historyMaxItems.toLong())
         writeObject(PwDatabaseV4XML.ElemHistoryMaxSize, mDatabaseV4.historyMaxSize)
-        writeObject(PwDatabaseV4XML.ElemLastSelectedGroup, mDatabaseV4.lastSelectedGroupUUID)
-        writeObject(PwDatabaseV4XML.ElemLastTopVisibleGroup, mDatabaseV4.lastTopVisibleGroupUUID)
+        writeUuid(PwDatabaseV4XML.ElemLastSelectedGroup, mDatabaseV4.lastSelectedGroupUUID)
+        writeUuid(PwDatabaseV4XML.ElemLastTopVisibleGroup, mDatabaseV4.lastTopVisibleGroupUUID)
 
         if (header!!.version < PwDbHeaderV4.FILE_VERSION_32_4) {
-            writeBinPool()
+            writeBinariesKDBX31()
         }
         writeCustomData(mDatabaseV4.customData)
 
@@ -306,13 +304,13 @@ class PwDbV4Output(private val mDatabaseV4: PwDatabaseV4, outputStream: OutputSt
     @Throws(IllegalArgumentException::class, IllegalStateException::class, IOException::class)
     private fun startGroup(group: PwGroupV4) {
         xml.startTag(null, PwDatabaseV4XML.ElemGroup)
-        writeObject(PwDatabaseV4XML.ElemUuid, group.id)
+        writeUuid(PwDatabaseV4XML.ElemUuid, group.id)
         writeObject(PwDatabaseV4XML.ElemName, group.title)
         writeObject(PwDatabaseV4XML.ElemNotes, group.notes)
         writeObject(PwDatabaseV4XML.ElemIcon, group.icon.iconId.toLong())
 
         if (group.iconCustom != PwIconCustom.UNKNOWN_ICON) {
-            writeObject(PwDatabaseV4XML.ElemCustomIconID, group.iconCustom.uuid)
+            writeUuid(PwDatabaseV4XML.ElemCustomIconID, group.iconCustom.uuid)
         }
 
         writeTimes(group)
@@ -320,7 +318,7 @@ class PwDbV4Output(private val mDatabaseV4: PwDatabaseV4, outputStream: OutputSt
         writeObject(PwDatabaseV4XML.ElemGroupDefaultAutoTypeSeq, group.defaultAutoTypeSequence)
         writeObject(PwDatabaseV4XML.ElemEnableAutoType, group.enableAutoType)
         writeObject(PwDatabaseV4XML.ElemEnableSearching, group.enableSearching)
-        writeObject(PwDatabaseV4XML.ElemLastTopVisibleEntry, group.lastTopVisibleEntry)
+        writeUuid(PwDatabaseV4XML.ElemLastTopVisibleEntry, group.lastTopVisibleEntry)
     }
 
     @Throws(IllegalArgumentException::class, IllegalStateException::class, IOException::class)
@@ -333,11 +331,11 @@ class PwDbV4Output(private val mDatabaseV4: PwDatabaseV4, outputStream: OutputSt
 
         xml.startTag(null, PwDatabaseV4XML.ElemEntry)
 
-        writeObject(PwDatabaseV4XML.ElemUuid, entry.id)
+        writeUuid(PwDatabaseV4XML.ElemUuid, entry.id)
         writeObject(PwDatabaseV4XML.ElemIcon, entry.icon.iconId.toLong())
 
         if (entry.iconCustom != PwIconCustom.UNKNOWN_ICON) {
-            writeObject(PwDatabaseV4XML.ElemCustomIconID, entry.iconCustom.uuid)
+            writeUuid(PwDatabaseV4XML.ElemCustomIconID, entry.iconCustom.uuid)
         }
 
         writeObject(PwDatabaseV4XML.ElemFgColor, entry.foregroundColor)
@@ -348,7 +346,7 @@ class PwDbV4Output(private val mDatabaseV4: PwDatabaseV4, outputStream: OutputSt
         writeTimes(entry)
 
         writeFields(entry.fields)
-        writeList(entry.binaries)
+        writeEntryBinaries(entry.binaries)
         writeAutoType(entry.autoType)
 
         if (!isHistory) {
@@ -358,81 +356,6 @@ class PwDbV4Output(private val mDatabaseV4: PwDatabaseV4, outputStream: OutputSt
         xml.endTag(null, PwDatabaseV4XML.ElemEntry)
     }
 
-
-    @Throws(IllegalArgumentException::class, IllegalStateException::class, IOException::class)
-    private fun writeObject(key: String, binary: ProtectedBinary) {
-
-        xml.startTag(null, PwDatabaseV4XML.ElemBinary)
-        xml.startTag(null, PwDatabaseV4XML.ElemKey)
-        xml.text(safeXmlString(key))
-        xml.endTag(null, PwDatabaseV4XML.ElemKey)
-
-        xml.startTag(null, PwDatabaseV4XML.ElemValue)
-        val ref = mDatabaseV4.binPool.findKey(binary)
-        if (ref != null) {
-            xml.attribute(null, PwDatabaseV4XML.AttrRef, ref.toString())
-        } else {
-            writeBinary(binary)
-        }
-        xml.endTag(null, PwDatabaseV4XML.ElemValue)
-
-        xml.endTag(null, PwDatabaseV4XML.ElemBinary)
-    }
-
-    @Throws(IllegalArgumentException::class, IllegalStateException::class, IOException::class)
-    private fun writeBinary(value: ProtectedBinary) {
-
-        val valLength = value.length().toInt()
-        if (valLength > 0) {
-            val buffer = ByteArray(valLength)
-            if (valLength == value.getData()!!.read(buffer, 0, valLength)) {
-
-                if (value.isProtected) {
-                    xml.attribute(null, PwDatabaseV4XML.AttrProtected, PwDatabaseV4XML.ValTrue)
-
-                    val encoded = ByteArray(valLength)
-                    randomStream!!.processBytes(buffer, 0, valLength, encoded, 0)
-                    xml.text(String(Base64.encode(encoded, BASE_64_FLAG)))
-
-                } else {
-                    if (mDatabaseV4.compressionAlgorithm === PwCompressionAlgorithm.GZip) {
-                        xml.attribute(null, PwDatabaseV4XML.AttrCompressed, PwDatabaseV4XML.ValTrue)
-
-                        val byteArrayOutputStream = ByteArrayOutputStream()
-                        val gzipOutputStream = GZIPOutputStream(byteArrayOutputStream)
-                        copyStream(ByteArrayInputStream(buffer), gzipOutputStream)
-                        // IOUtils.copy(ByteArrayInputStream(ByteArrayInputStream(buffer)), gzipOutputStream)
-                        gzipOutputStream.close()
-
-                        xml.text(String(Base64.encode(byteArrayOutputStream.toByteArray(), BASE_64_FLAG)))
-
-                    } else {
-                        xml.text(String(Base64.encode(buffer, BASE_64_FLAG)))
-                    }
-                }
-            } else {
-                Log.e(TAG, "Unable to read the stream of the protected binary")
-            }
-        }
-    }
-
-    @Throws(IOException::class)
-    fun copyStream(inputStream: InputStream, out: OutputStream) {
-        val buffer = ByteArray(BUFFER_SIZE_BYTES)
-        try {
-            var read = inputStream.read(buffer)
-            while (read != -1) {
-                out.write(buffer, 0, read)
-                read = inputStream.read(buffer)
-                if (Thread.interrupted()) {
-                    throw InterruptedException()
-                }
-            }
-        } catch (error: OutOfMemoryError) {
-            throw IOException(error)
-        }
-    }
-
     @Throws(IllegalArgumentException::class, IllegalStateException::class, IOException::class)
     private fun writeObject(name: String, value: String, filterXmlChars: Boolean = false) {
         var xmlString = value
@@ -477,11 +400,57 @@ class PwDbV4Output(private val mDatabaseV4: PwDatabaseV4, outputStream: OutputSt
     }
 
     @Throws(IllegalArgumentException::class, IllegalStateException::class, IOException::class)
-    private fun writeObject(name: String, uuid: UUID) {
+    private fun writeUuid(name: String, uuid: UUID) {
         val data = DatabaseInputOutputUtils.uuidToBytes(uuid)
         writeObject(name, String(Base64.encode(data, BASE_64_FLAG)))
     }
 
+    // Only for KDBX3.1-
+    @Throws(IllegalArgumentException::class, IllegalStateException::class, IOException::class)
+    private fun writeBinariesKDBX31() {
+        xml.startTag(null, PwDatabaseV4XML.ElemBinaries)
+
+        mDatabaseV4.binPool.doForEachBinary { key, binary ->
+            xml.startTag(null, PwDatabaseV4XML.ElemBinary)
+            xml.attribute(null, PwDatabaseV4XML.AttrId, key.toString())
+            xml.attribute(null, PwDatabaseV4XML.AttrCompressed,
+                    if (mDatabaseV4.compressionAlgorithm === PwCompressionAlgorithm.GZip) {
+                        PwDatabaseV4XML.ValTrue
+                    } else {
+                        PwDatabaseV4XML.ValFalse
+                    }
+            )
+            /*
+            // TODO compression needed here ?
+                // Binary need to be compressed before storage
+                val byteArrayOutputStream = ByteArrayOutputStream()
+                val gzipOutputStream = GZIPOutputStream(byteArrayOutputStream)
+                IOUtils.copy(binary.getInputDataStream(), gzipOutputStream)
+                gzipOutputStream.close()
+                readFromStream(ByteArrayInputStream(byteArrayOutputStream.toByteArray()), BUFFER_SIZE_BYTES,
+                        object : ReadBytes {
+                            override fun read(buffer: ByteArray) {
+                                xml.text(String(Base64.encode(buffer, BASE_64_FLAG)))
+                            }
+                        }
+                )
+            }*/
+
+            readFromStream(binary.getInputDataStream(), BUFFER_SIZE_BYTES,
+                    object : ReadBytes {
+                        override fun read(buffer: ByteArray) {
+                            val charArray = String(Base64.encode(buffer, BASE_64_FLAG)).toCharArray()
+                            xml.text(charArray, 0, charArray.size)
+                        }
+                    }
+            )
+
+            xml.endTag(null, PwDatabaseV4XML.ElemBinary)
+        }
+
+        xml.endTag(null, PwDatabaseV4XML.ElemBinaries)
+    }
+
     @Throws(IllegalArgumentException::class, IllegalStateException::class, IOException::class)
     private fun writeObject(name: String, keyName: String, keyValue: String, valueName: String, valueValue: String) {
         xml.startTag(null, name)
@@ -565,20 +534,58 @@ class PwDbV4Output(private val mDatabaseV4: PwDatabaseV4, outputStream: OutputSt
     private fun writeDeletedObject(value: PwDeletedObject) {
         xml.startTag(null, PwDatabaseV4XML.ElemDeletedObject)
 
-        writeObject(PwDatabaseV4XML.ElemUuid, value.uuid)
+        writeUuid(PwDatabaseV4XML.ElemUuid, value.uuid)
         writeObject(PwDatabaseV4XML.ElemDeletionTime, value.deletionTime)
 
         xml.endTag(null, PwDatabaseV4XML.ElemDeletedObject)
     }
 
     @Throws(IllegalArgumentException::class, IllegalStateException::class, IOException::class)
-    private fun writeList(binaries: Map<String, ProtectedBinary>) {
-        for ((key, value) in binaries) {
-            writeObject(key, value)
+    private fun writeEntryBinaries(binaries: Map<String, ProtectedBinary>) {
+        for ((key, binary) in binaries) {
+            xml.startTag(null, PwDatabaseV4XML.ElemBinary)
+            xml.startTag(null, PwDatabaseV4XML.ElemKey)
+            xml.text(safeXmlString(key))
+            xml.endTag(null, PwDatabaseV4XML.ElemKey)
+
+            xml.startTag(null, PwDatabaseV4XML.ElemValue)
+            val ref = mDatabaseV4.binPool.findKey(binary)
+            if (ref != null) {
+                xml.attribute(null, PwDatabaseV4XML.AttrRef, ref.toString())
+            } else {
+                val binaryLength = binary.length()
+                if (binaryLength > 0) {
+
+                    if (binary.isProtected) {
+                        xml.attribute(null, PwDatabaseV4XML.AttrProtected, PwDatabaseV4XML.ValTrue)
+
+                        readFromStream(binary.getInputDataStream(), BUFFER_SIZE_BYTES,
+                                object : ReadBytes {
+                                    override fun read(buffer: ByteArray) {
+                                        val encoded = ByteArray(buffer.size)
+                                        randomStream!!.processBytes(buffer, 0, encoded.size, encoded, 0)
+                                        val charArray = String(Base64.encode(encoded, BASE_64_FLAG)).toCharArray()
+                                        xml.text(charArray, 0, charArray.size)
+                                    }
+                                })
+                    } else {
+                        readFromStream(binary.getInputDataStream(), BUFFER_SIZE_BYTES,
+                                object : ReadBytes {
+                                    override fun read(buffer: ByteArray) {
+                                        val charArray = String(Base64.encode(buffer, BASE_64_FLAG)).toCharArray()
+                                        xml.text(charArray, 0, charArray.size)
+                                    }
+                                }
+                        )
+                    }
+                }
+            }
+            xml.endTag(null, PwDatabaseV4XML.ElemValue)
+
+            xml.endTag(null, PwDatabaseV4XML.ElemBinary)
         }
     }
 
-
     @Throws(IllegalArgumentException::class, IllegalStateException::class, IOException::class)
     private fun writeDeletedObjects(value: List<PwDeletedObject>) {
         xml.startTag(null, PwDatabaseV4XML.ElemDeletedObjects)
@@ -658,7 +665,7 @@ class PwDbV4Output(private val mDatabaseV4: PwDatabaseV4, outputStream: OutputSt
         for (icon in customIcons) {
             xml.startTag(null, PwDatabaseV4XML.ElemCustomIconItem)
 
-            writeObject(PwDatabaseV4XML.ElemCustomIconItemID, icon.uuid)
+            writeUuid(PwDatabaseV4XML.ElemCustomIconItemID, icon.uuid)
             writeObject(PwDatabaseV4XML.ElemCustomIconItemData, String(Base64.encode(icon.imageData, BASE_64_FLAG)))
 
             xml.endTag(null, PwDatabaseV4XML.ElemCustomIconItem)
@@ -667,22 +674,6 @@ class PwDbV4Output(private val mDatabaseV4: PwDatabaseV4, outputStream: OutputSt
         xml.endTag(null, PwDatabaseV4XML.ElemCustomIcons)
     }
 
-    @Throws(IllegalArgumentException::class, IllegalStateException::class, IOException::class)
-    private fun writeBinPool() {
-        xml.startTag(null, PwDatabaseV4XML.ElemBinaries)
-
-        mDatabaseV4.binPool.doForEachBinary { key, binary ->
-            xml.startTag(null, PwDatabaseV4XML.ElemBinary)
-            xml.attribute(null, PwDatabaseV4XML.AttrId, key.toString())
-
-            writeBinary(binary)
-
-            xml.endTag(null, PwDatabaseV4XML.ElemBinary)
-        }
-
-        xml.endTag(null, PwDatabaseV4XML.ElemBinaries)
-    }
-
     private fun safeXmlString(text: String): String {
         if (text.isEmpty()) {
             return text
diff --git a/app/src/main/java/com/kunzisoft/keepass/stream/ActionReadBytes.java b/app/src/main/java/com/kunzisoft/keepass/stream/ActionReadBytes.java
deleted file mode 100644
index d72ecb2a4..000000000
--- a/app/src/main/java/com/kunzisoft/keepass/stream/ActionReadBytes.java
+++ /dev/null
@@ -1,11 +0,0 @@
-package com.kunzisoft.keepass.stream;
-
-import java.io.IOException;
-
-public interface ActionReadBytes {
-    /**
-     * Called after each buffer fill
-     * @param buffer filled
-     */
-    void doAction(byte[] buffer) throws IOException;
-}
diff --git a/app/src/main/java/com/kunzisoft/keepass/stream/LEDataInputStream.java b/app/src/main/java/com/kunzisoft/keepass/stream/LEDataInputStream.java
index 7af2f021e..ead0413de 100644
--- a/app/src/main/java/com/kunzisoft/keepass/stream/LEDataInputStream.java
+++ b/app/src/main/java/com/kunzisoft/keepass/stream/LEDataInputStream.java
@@ -124,7 +124,7 @@ public class LEDataInputStream extends InputStream {
         return buf;
     }
 
-    public void readBytes(int length, ActionReadBytes actionReadBytes) throws IOException {
+    public void readBytes(int length, ReadBytes readBytes) throws IOException {
         int bufferSize = 256 * 3; // TODO Buffer size
         byte[] buffer = new byte[bufferSize];
 
@@ -146,7 +146,7 @@ public class LEDataInputStream extends InputStream {
             } else {
                 optimizedBuffer = buffer;
             }
-            actionReadBytes.doAction(optimizedBuffer);
+            readBytes.read(optimizedBuffer);
             offset += read;
         }
     }
diff --git a/app/src/main/java/com/kunzisoft/keepass/stream/ReadBytes.kt b/app/src/main/java/com/kunzisoft/keepass/stream/ReadBytes.kt
new file mode 100644
index 000000000..3c03dabd4
--- /dev/null
+++ b/app/src/main/java/com/kunzisoft/keepass/stream/ReadBytes.kt
@@ -0,0 +1,30 @@
+package com.kunzisoft.keepass.stream
+
+import java.io.IOException
+import java.io.InputStream
+
+interface ReadBytes {
+    /**
+     * Called after each buffer fill
+     * @param buffer filled
+     */
+    @Throws(IOException::class)
+    fun read(buffer: ByteArray)
+}
+
+@Throws(IOException::class)
+fun readFromStream(inputStream: InputStream, bufferSize: Int, readBytes: ReadBytes) {
+    val buffer = ByteArray(bufferSize)
+    var read = 0
+    while (read != -1) {
+        read = inputStream.read(buffer, 0, buffer.size)
+        if (read != -1) {
+            val optimizedBuffer: ByteArray = if (buffer.size == read) {
+                buffer
+            } else {
+                buffer.copyOf(read)
+            }
+            readBytes.read(optimizedBuffer)
+        }
+    }
+}