diff --git a/core/java/src/net/i2p/data/KeyCertificate.java b/core/java/src/net/i2p/data/KeyCertificate.java
index 87374186c8..3645f44c9f 100644
--- a/core/java/src/net/i2p/data/KeyCertificate.java
+++ b/core/java/src/net/i2p/data/KeyCertificate.java
@@ -258,7 +258,8 @@ public class KeyCertificate extends Certificate {
         if (_payload == null) {
             buf.append(" null payload");
         } else {
-            buf.append("\n\tCrypto type: ").append(getCryptoTypeCode());
+            buf.append("\n\tCrypto type: ").append(getCryptoTypeCode())
+               .append(" (").append(getSigType()).append(')');
             buf.append("\n\tSig type: ").append(getSigTypeCode())
                .append(" (").append(getSigType()).append(')');
             if (_payload.length > HEADER_LENGTH)
diff --git a/core/java/src/net/i2p/data/PrivateKeyFile.java b/core/java/src/net/i2p/data/PrivateKeyFile.java
index f4d122e701..9de313047d 100644
--- a/core/java/src/net/i2p/data/PrivateKeyFile.java
+++ b/core/java/src/net/i2p/data/PrivateKeyFile.java
@@ -2,7 +2,6 @@ package net.i2p.data;
 
 
 import java.io.BufferedInputStream;
-import java.io.ByteArrayInputStream;
 import java.io.File;
 import java.io.FileInputStream;
 import java.io.FileOutputStream;
diff --git a/core/java/src/net/i2p/data/SimpleDataStructure.java b/core/java/src/net/i2p/data/SimpleDataStructure.java
index 707253fc30..e328fa5611 100644
--- a/core/java/src/net/i2p/data/SimpleDataStructure.java
+++ b/core/java/src/net/i2p/data/SimpleDataStructure.java
@@ -13,11 +13,6 @@ import net.i2p.crypto.SHA256Generator;
 
 /**
  * A SimpleDataStructure contains only a single fixed-length byte array.
- * The main reason to do this is to override
- * toByteArray() and fromByteArray(), which are used by toBase64(), fromBase64(),
- * and calculateHash() in DataStructureImpl - otherwise these would go through
- * a wasteful array-to-stream-to-array pass.
- * It also centralizes a lot of common code.
  *
  * Implemented in 0.8.2 and retrofitted over several of the classes in this package.
  *
@@ -27,10 +22,12 @@ import net.i2p.crypto.SHA256Generator;
  * subsequent attempts to set the data via setData(), readBytes(),
  * fromByteArray(), or fromBase64() will throw a RuntimeException.
  *
+ * As of 0.9.48, no longer extends DataStrucureImpl to save space
+ *
  * @since 0.8.2
  * @author zzz
  */
-public abstract class SimpleDataStructure extends DataStructureImpl {
+public abstract class SimpleDataStructure implements DataStructure {
     protected byte[] _data;
     
     /** A new instance with the data set to null. Call readBytes(), setData(), or fromByteArray() after this to set the data */
@@ -83,13 +80,22 @@ public abstract class SimpleDataStructure extends DataStructureImpl {
         // Throws on incomplete read
         read(in, _data);
     }
+
+    /**
+     * Repeated reads until the buffer is full or IOException is thrown
+     *
+     * @return number of bytes read (should always equal target.length)
+     * @since 0.9.48, copied from former superclass DataStructureImpl
+     */
+    protected int read(InputStream in, byte target[]) throws IOException {
+        return DataHelper.read(in, target);
+    }
     
     public void writeBytes(OutputStream out) throws DataFormatException, IOException {
         if (_data == null) throw new DataFormatException("No data to write out");
         out.write(_data);
     }
     
-    @Override
     public String toBase64() {
         if (_data == null)
             return null;
@@ -101,7 +107,6 @@ public abstract class SimpleDataStructure extends DataStructureImpl {
      * @throws DataFormatException if decoded data is not the legal number of bytes or on decoding error
      * @throws RuntimeException if data already set.
      */
-    @Override
     public void fromBase64(String data) throws DataFormatException {
         if (data == null) throw new DataFormatException("Null data passed in");
         byte[] d = Base64.decode(data);
@@ -114,29 +119,24 @@ public abstract class SimpleDataStructure extends DataStructureImpl {
     }
 
     /** @return the SHA256 hash of the byte array, or null if the data is null */
-    @Override
     public Hash calculateHash() {
         if (_data != null) return SHA256Generator.getInstance().calculateHash(_data);
         return null;
     }
 
     /**
-     * Overridden for efficiency.
      * @return same thing as getData()
      */
-    @Override
     public byte[] toByteArray() {
         return _data;
     }
 
     /**
-     * Overridden for efficiency.
      * Does the same thing as setData() but null not allowed.
      * @param data non-null
      * @throws DataFormatException if null or wrong length
      * @throws RuntimeException if data already set.
      */
-    @Override
     public void fromByteArray(byte data[]) throws DataFormatException {
         if (data == null) throw new DataFormatException("Null data passed in");
         if (data.length != length())
diff --git a/core/java/src/net/i2p/data/i2cp/CreateSessionMessage.java b/core/java/src/net/i2p/data/i2cp/CreateSessionMessage.java
index 0df5f99fed..20adf8ff9c 100644
--- a/core/java/src/net/i2p/data/i2cp/CreateSessionMessage.java
+++ b/core/java/src/net/i2p/data/i2cp/CreateSessionMessage.java
@@ -56,7 +56,7 @@ public class CreateSessionMessage extends I2CPMessageImpl {
     protected byte[] doWriteMessage() throws I2CPMessageException, IOException {
         if (_sessionConfig == null)
             throw new I2CPMessageException("Unable to write out the message as there is not enough data");
-        ByteArrayOutputStream os = new ByteArrayOutputStream(64);
+        ByteArrayOutputStream os = new ByteArrayOutputStream(512);
         try {
             _sessionConfig.writeBytes(os);
         } catch (DataFormatException dfe) {
diff --git a/core/java/src/net/i2p/data/i2cp/DestLookupMessage.java b/core/java/src/net/i2p/data/i2cp/DestLookupMessage.java
index 2493898b78..f4126411a5 100644
--- a/core/java/src/net/i2p/data/i2cp/DestLookupMessage.java
+++ b/core/java/src/net/i2p/data/i2cp/DestLookupMessage.java
@@ -5,7 +5,6 @@ package net.i2p.data.i2cp;
  * with no warranty of any kind, either expressed or implied.  
  */
 
-import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
 
@@ -32,27 +31,17 @@ public class DestLookupMessage extends I2CPMessageImpl {
     }
 
     protected void doReadMessage(InputStream in, int size) throws I2CPMessageException, IOException {
-        //Hash h = new Hash();
         try {
-            //h.readBytes(in);
             _hash = Hash.create(in);
-        //} catch (DataFormatException dfe) {
         } catch (IllegalArgumentException dfe) {
             throw new I2CPMessageException("Unable to load the hash", dfe);
         }
-        //_hash = h;
     }
 
     protected byte[] doWriteMessage() throws I2CPMessageException, IOException {
         if (_hash == null)
             throw new I2CPMessageException("Unable to write out the message as there is not enough data");
-        ByteArrayOutputStream os = new ByteArrayOutputStream(Hash.HASH_LENGTH);
-        try {
-            _hash.writeBytes(os);
-        } catch (DataFormatException dfe) {
-            throw new I2CPMessageException("Error writing out the hash", dfe);
-        }
-        return os.toByteArray();
+        return _hash.getData();
     }
 
     public int getType() {
diff --git a/core/java/src/net/i2p/data/i2cp/ReconfigureSessionMessage.java b/core/java/src/net/i2p/data/i2cp/ReconfigureSessionMessage.java
index 7532af3580..174df491c4 100644
--- a/core/java/src/net/i2p/data/i2cp/ReconfigureSessionMessage.java
+++ b/core/java/src/net/i2p/data/i2cp/ReconfigureSessionMessage.java
@@ -71,7 +71,7 @@ public class ReconfigureSessionMessage extends I2CPMessageImpl {
     protected byte[] doWriteMessage() throws I2CPMessageException, IOException {
         if (_sessionId == null || _sessionConfig == null)
             throw new I2CPMessageException("Unable to write out the message as there is not enough data");
-        ByteArrayOutputStream os = new ByteArrayOutputStream(64);
+        ByteArrayOutputStream os = new ByteArrayOutputStream(1024);
         try {
             _sessionId.writeBytes(os);
             _sessionConfig.writeBytes(os);