diff --git a/onionr/communicator2.py b/onionr/communicator2.py
index 67a61e19..ccddc1cf 100755
--- a/onionr/communicator2.py
+++ b/onionr/communicator2.py
@@ -28,7 +28,7 @@ class OnionrCommunicatorDaemon:
         logger.warn('New (unstable) communicator is being used.')
 
         self.timers = []
-        self._core = core.Core()
+        self._core = core.Core(torPort=sys.argv[2])
         self.nistSaltTimestamp = 0
         self.powSalt = 0
         self.delay = 1
diff --git a/onionr/core.py b/onionr/core.py
index 0d9aafde..9f10d762 100644
--- a/onionr/core.py
+++ b/onionr/core.py
@@ -20,7 +20,7 @@
 import sqlite3, os, sys, time, math, base64, tarfile, getpass, simplecrypt, hashlib, nacl, logger, json, netcontroller, math, config
 from onionrblockapi import Block
 
-import onionrutils, onionrcrypto, onionrproofs, onionrevents as events
+import onionrutils, onionrcrypto, onionrproofs, onionrevents as events, onionrexceptions, onionrvalues
 
 if sys.version_info < (3, 6):
     try:
@@ -30,7 +30,7 @@ if sys.version_info < (3, 6):
         sys.exit(1)
 
 class Core:
-    def __init__(self):
+    def __init__(self, torPort=0):
         '''
             Initialize Core Onionr library
         '''
@@ -44,6 +44,7 @@ class Core:
 
             self.bootstrapFileLocation = 'static-data/bootstrap-nodes.txt'
             self.bootstrapList = []
+            self.requirements = onionrvalues.OnionrValues()
 
             if not os.path.exists('data/'):
                 os.mkdir('data/')
@@ -659,11 +660,49 @@ class Core:
         conn.close()
         return True
 
-    def insertBlock(self, data, header='txt', sign=False, metadata = {}):
+    def insertBlock(self, data, header='txt', sign=False, encryptType='', symKey='', asymPeer='', meta = {}):
         '''
             Inserts a block into the network
+            encryptType must be specified to encrypt a block
         '''
 
+        try:
+            data.decode()
+        except AttributeError:
+            data = data.encode()
+
+        retData = ''
+        signature = ''
+        signer = ''
+
+        # only use header if not set in provided meta
+        try:
+            meta['type']
+        except KeyError:
+            meta['type'] = header # block type
+
+        jsonMeta = json.dumps(meta)
+
+        if encryptType in ('asym', 'sym'):
+            metadata['encryptType'] = encryptType
+        else:
+            raise onionrexceptions.InvalidMetadata('encryptType must be asym or sym')
+
+        # sign before encrypt, as unauthenticated crypto should not be a problem here
+        if sign:
+            signature = self._crypto.edSign(jsonMeta + data, key=self._crypto.privKey, encodeResult=True)
+            signer = self._crypto.pubKeyHashID()
+
+        if len(jsonMeta) > 1000:
+            raise onionrexceptions.InvalidMetadata('meta in json encoded form must not exceed 1000 bytes')
+        
+        if encryptType == 'sym':
+            if len(symKey) < self.requirements.passwordLength:
+                raise onionrexceptions.SecurityError('Weak encryption key')
+            jsonMeta = self._crypto.symmetricEncrypt(jsonMeta, key=symKey, returnEncoded=True)
+
+        metadata['meta'] = jsonMeta
+
         powProof = onionrproofs.POW(data)
         powToken = ''
         # wait for proof to complete
@@ -685,41 +724,7 @@ class Core:
             powProof.shutdown()
             return ''
 
-        try:
-            data.decode()
-        except AttributeError:
-            data = data.encode()
 
-        retData = ''
-
-        metadata['type'] = header
-        metadata['powRandomToken'] = powToken
-
-        sig = {}
-
-        metadata = json.dumps(metadata)
-        metadata = metadata.encode()
-        signature = ''
-
-        if sign:
-            signature = self._crypto.edSign(metadata + b'\n' + data, self._crypto.privKey, encodeResult=True)
-            ourID = self._crypto.pubKeyHashID()
-            # Convert from bytes on some py versions?
-            try:
-                ourID = ourID.decode()
-            except AttributeError:
-                pass
-        metadata = {'sig': signature, 'meta': metadata.decode()}
-        metadata = json.dumps(metadata)
-        metadata = metadata.encode()
-
-        if len(data) == 0:
-            logger.error('Will not insert empty block')
-        else:
-            addedHash = self.setData(metadata + b'\n' + data)
-            self.addToBlockDB(addedHash, selfInsert=True)
-            self.setBlockType(addedHash, header)
-            retData = addedHash
         return retData
 
     def introduceNode(self):
diff --git a/onionr/onionrexceptions.py b/onionr/onionrexceptions.py
index 43077e67..aa00e65d 100644
--- a/onionr/onionrexceptions.py
+++ b/onionr/onionrexceptions.py
@@ -26,6 +26,10 @@ class Unknown(Exception):
 class Invalid(Exception):
     pass
 
+# block exceptions
+class InvalidMetadata(Exception):
+    pass
+
 # network level exceptions
 class MissingPort(Exception):
     pass
diff --git a/onionr/onionrvalues.py b/onionr/onionrvalues.py
new file mode 100644
index 00000000..b9fd4a2b
--- /dev/null
+++ b/onionr/onionrvalues.py
@@ -0,0 +1,24 @@
+'''
+    Onionr - P2P Microblogging Platform & Social network
+
+    This file defines values and requirements used by Onionr
+'''
+'''
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+'''
+
+class OnionrValues:
+    def __init__(self):
+        self.passwordLength = 20
+        self.blockMetadataLengths = {'meta': 1000, 'sig': 88, 'signer': 64, 'time': 10, 'powRandomToken': '1000'}
\ No newline at end of file