diff --git a/src/saml2/eptid.py b/src/saml2/eptid.py
index dd66d8f..7e0905e 100644
--- a/src/saml2/eptid.py
+++ b/src/saml2/eptid.py
@@ -1,6 +1,6 @@
 # An eduPersonTargetedID comprises
 # the entity name of the identity provider, the entity name of the service 
-# provider, and the opaque string value. 
+# provider, and a opaque string value.
 # These strings are separated by "!" symbols. This form is advocated by 
 # Internet2 and may overtake the other form in due course.
 
@@ -33,13 +33,13 @@ class Eptid(object):
     def __setitem__(self, key, value):
         self._db[key] = value
 
-    def get(self, idp, sp, args):
+    def get(self, idp, sp, *args):
         # key is a combination of sp_entity_id and object id
-        key = (".".join([sp, args[0]])).encode("utf-8")
+        key = ("__".join([sp, args[0]])).encode("utf-8")
         try:
             return self[key]
         except KeyError:
-            val = self.make(idp, sp, args[1])
+            val = self.make(idp, sp, args)
             self[key] = val
             return val
 
diff --git a/src/saml2/mdstore.py b/src/saml2/mdstore.py
index 68650d5..30b69a2 100644
--- a/src/saml2/mdstore.py
+++ b/src/saml2/mdstore.py
@@ -97,6 +97,18 @@ class MetaData(object):
         self.entity = {}
         self.metadata = metadata
 
+    def items(self):
+        return self.entity
+
+    def keys(self):
+        return self.entity.keys()
+
+    def __contains__(self, item):
+        return item in self.entity
+
+    def __getitem__(self, item):
+        return self.entity[item]
+
     def do_entity_descriptor(self, entity_descr):
         try:
             if not valid(entity_descr.valid_until):
@@ -530,19 +542,19 @@ class MetadataStore(object):
 
     def attribute_requirement(self, entity_id, index=0):
         for md in self.metadata.values():
-            if entity_id in md.entity:
+            if entity_id in md.items():
                 return md.attribute_requirement(entity_id, index)
 
     def keys(self):
         res = []
         for md in self.metadata.values():
-            res.extend(md.entity.keys())
+            res.extend(md.keys())
         return res
 
     def __getitem__(self, item):
         for md in self.metadata.values():
             try:
-                return md.entity[item]
+                return md[item]
             except KeyError:
                 pass
 
@@ -554,7 +566,7 @@ class MetadataStore(object):
     def entities(self):
         num = 0
         for md in self.metadata.values():
-            num += len(md.entity)
+            num += len(md.items())
 
         return num
 
@@ -569,8 +581,8 @@ class MetadataStore(object):
 
     def name(self, entity_id, langpref="en"):
         for md in self.metadata.values():
-            if entity_id in md.entity:
-                return name(md.entity[entity_id], langpref)
+            if entity_id in md.items():
+                return name(md[entity_id], langpref)
         return None
 
     def certs(self, entity_id, descriptor, use="signing"):
@@ -618,7 +630,7 @@ class MetadataStore(object):
 
     def bindings(self, entity_id, typ, service):
         for md in self.metadata.values():
-            if entity_id in md.entity:
+            if entity_id in md.items():
                 return md.bindings(entity_id, typ, service)
 
         return None
@@ -639,5 +651,5 @@ class MetadataStore(object):
     def items(self):
         res = {}
         for md in self.metadata.values():
-            res.update(md.entity)
+            res.update(md.items())
         return res.items()
diff --git a/src/saml2/mongo_store.py b/src/saml2/mongo_store.py
index 25a36b0..c60d888 100644
--- a/src/saml2/mongo_store.py
+++ b/src/saml2/mongo_store.py
@@ -208,9 +208,9 @@ class MDB(object):
         doc.update(kwargs)
         _ = self.db.insert(doc)
 
-    def get(self, key=None, **kwargs):
-        if key:
-            doc = {self.primary_key: key}
+    def get(self, value=None, **kwargs):
+        if value:
+            doc = {self.primary_key: value}
             doc.update(kwargs)
             return [item for item in self.db.find(doc)]
         elif kwargs:
@@ -249,27 +249,23 @@ class MDB(object):
 
 #------------------------------------------------------------------------------
 class EptidMDB(Eptid):
-    primary_key = "eptid"
 
-    def __init__(self, secret, collection="", sub_collection=""):
+    def __init__(self, secret, collection="", sub_collection="eptid"):
         Eptid.__init__(self, secret)
         self.mdb = MDB(collection, sub_collection)
-        self.mdb.primary_key = "entity_id"
+        self.mdb.primary_key = "eptid_key"
 
     def __getitem__(self, key):
         res = self.mdb.get(key)
         if not res:
             raise KeyError(key)
         elif len(res) == 1:
-            return res[0]
+            return res[0]["eptid"]
         else:
             raise CorruptDatabase("Found more than one EPTID document")
 
     def __setitem__(self, key, value):
-        if key == self.mdb.primary_key:
-            _ = self.mdb.store(value)
-        else:
-            _ = self.mdb.store(**{key: value})
+        _ = self.mdb.store(key, **{"eptid": value})
 
 
 #------------------------------------------------------------------------------
diff --git a/tests/test_72_eptid.py b/tests/test_72_eptid.py
new file mode 100644
index 0000000..ea95d89
--- /dev/null
+++ b/tests/test_72_eptid.py
@@ -0,0 +1,41 @@
+from saml2.eptid import Eptid, EptidShelve
+
+__author__ = 'rolandh'
+
+
+def test_eptid():
+    edb = Eptid("secret")
+    e1 = edb.get("idp_entity_id", "sp_entity_id", "user_id", "some other data")
+    print e1
+    assert e1.startswith("idp_entity_id!sp_entity_id!")
+    e2 = edb.get("idp_entity_id", "sp_entity_id", "user_id", "some other data")
+    assert e1 == e2
+
+    e3 = edb.get("idp_entity_id", "sp_entity_id", "user_2", "some other data")
+    print e3
+    assert e1 != e3
+
+    e4 = edb.get("idp_entity_id", "sp_entity_id2", "user_id", "some other data")
+    assert e4 != e1
+    assert e4 != e3
+
+
+def test_eptid_shelve():
+    edb = EptidShelve("secret", "eptid.db")
+    e1 = edb.get("idp_entity_id", "sp_entity_id", "user_id", "some other data")
+    print e1
+    assert e1.startswith("idp_entity_id!sp_entity_id!")
+    e2 = edb.get("idp_entity_id", "sp_entity_id", "user_id", "some other data")
+    assert e1 == e2
+
+    e3 = edb.get("idp_entity_id", "sp_entity_id", "user_2", "some other data")
+    print e3
+    assert e1 != e3
+
+    e4 = edb.get("idp_entity_id", "sp_entity_id2", "user_id", "some other data")
+    assert e4 != e1
+    assert e4 != e3
+
+
+if __name__ == "__main__":
+    test_eptid_shelve()
\ No newline at end of file
diff --git a/tests/test_71_mongodb.py b/tests/test_75_mongodb.py
similarity index 73%
rename from tests/test_71_mongodb.py
rename to tests/test_75_mongodb.py
index d8b7f05..a3e2a10 100644
--- a/tests/test_71_mongodb.py
+++ b/tests/test_75_mongodb.py
@@ -2,6 +2,7 @@ from saml2 import BINDING_HTTP_POST
 from saml2.saml import AUTHN_PASSWORD
 from saml2.client import Saml2Client
 from saml2.server import Server
+from saml2.mongo_store import EptidMDB
 
 __author__ = 'rolandh'
 
@@ -50,5 +51,26 @@ def test_flow():
     nids = idp2.ident.find_nameid("jeter")
     assert len(nids) == 1
 
+
+def test_eptid_mongo_db():
+    edb = EptidMDB("secret", "idp")
+    e1 = edb.get("idp_entity_id", "sp_entity_id", "user_id",
+                 "some other data")
+    print e1
+    assert e1.startswith("idp_entity_id!sp_entity_id!")
+    e2 = edb.get("idp_entity_id", "sp_entity_id", "user_id",
+                 "some other data")
+    assert e1 == e2
+
+    e3 = edb.get("idp_entity_id", "sp_entity_id", "user_2",
+                 "some other data")
+    print e3
+    assert e1 != e3
+
+    e4 = edb.get("idp_entity_id", "sp_entity_id2", "user_id",
+                 "some other data")
+    assert e4 != e1
+    assert e4 != e3
+
 if __name__ == "__main__":
     test_flow()