diff --git a/soter/models/auth.py b/soter/models/auth.py
index b6abbe1..a83f30f 100644
--- a/soter/models/auth.py
+++ b/soter/models/auth.py
@@ -37,7 +37,7 @@ class User(Base):
     _password = Column('password', Unicode(64))
     locked_out = Column('locked_out', Boolean)
 
-    roles = relationship("Role", secondary=role_user)
+    roles = relationship("Role", secondary=role_user, backref='users')
 
     def _get_password(self):
         return self._password
diff --git a/soter/models/master.py b/soter/models/master.py
index a7494c9..7354e65 100644
--- a/soter/models/master.py
+++ b/soter/models/master.py
@@ -1,6 +1,8 @@
 import uuid
+import re
 
-from sqlalchemy import Column, PickleType, Unicode, ForeignKey, Boolean, Table, UniqueConstraint
+from sqlalchemy import Column, PickleType, Unicode, ForeignKey, Boolean, Table, UniqueConstraint, LargeBinary
+from sqlalchemy.ext.hybrid import hybrid_property
 
 from sqlalchemy.orm import relationship
 
@@ -8,6 +10,11 @@ from soter.models import Base, DBSession
 from soter.models.guidtype import GUID
 
 
+def semantic_name(name):
+    p = re.compile('([!\*’\(\);:@&=\+\$,/\?#\[\] ])')
+    return p.sub('-', name)
+
+
 class DbSetting(Base):
     __tablename__ = 'settings'
 
@@ -43,12 +50,21 @@ picture_tag = Table(
     UniqueConstraint('picture_id', 'tag_id')
 )
 
+picture_album = Table(
+    'picture_albums', Base.metadata,
+    Column('id', GUID(), primary_key=True, default=uuid.uuid4),
+    Column('picture_id', GUID(), ForeignKey('pictures.id'), nullable=False),
+    Column('album_id', GUID(), ForeignKey('albums.id'), nullable=False),
+    UniqueConstraint('picture_id', 'album_id')
+)
+
 
 class Album(Base):
     __tablename__ = 'albums'
 
     id = Column('id', GUID(), primary_key=True, default=uuid.uuid4)
-    name = Column('name', Unicode(255), unique=True, nullable=False)
+    _name = Column('name', Unicode(255), unique=True, nullable=False)
+    semantic = Column('semantic', Unicode(255), unique=True, nullable=False)
     description = Column('description', Unicode(255))
     user_id = Column('user_id', GUID(), ForeignKey('users.id'), nullable=False)
     is_fixture = Column('is_fixture', Boolean, nullable=False)
@@ -56,7 +72,14 @@ class Album(Base):
 
     user = relationship('User', primaryjoin="User.id==Album.user_id", cascade=None)
 
-    pictures = relationship('Picture', backref='album')
+    @hybrid_property
+    def name(self):
+        return self._name
+
+    @name.setter
+    def name(self, name):
+        self.name = name
+        self.semantic = semantic_name(name)
 
     def __init__(self, name, description, user_id, is_public, id=None, is_fixture=False):
         self.name = name
@@ -95,20 +118,19 @@ class Picture(Base):
     __tablename__ = 'pictures'
 
     id = Column('id', GUID(), primary_key=True, default=uuid.uuid4)
-    name = Column('name', Unicode(255), unique=True)
-    url = Column('url', Unicode(255), unique=True)
+    name = Column('name', Unicode(255), nullable=False)
+    hash = Column('hash', LargeBinary(512), unique=True, nullable=False)
     user_id = Column('user_id', GUID(), ForeignKey('users.id'), nullable=False)
-    album_id = Column('album_id', GUID(), ForeignKey('albums.id'), nullable=False)
     is_public = Column('is_public', Boolean, nullable=False)
 
     tags = relationship("Tag", secondary=picture_tag)
+    albums = relationship("Album", secondary=picture_album, backref='pictures')
     user = relationship('User', primaryjoin="User.id==Picture.user_id", cascade=None)
 
-    def __init__(self, name, url, user_id, album_id, is_public, id=None, is_fixture=False):
+    def __init__(self, name, hash, user_id, is_public, id=None, is_fixture=False):
         self.name = name
-        self.url = url
+        self.hash = hash
         self.user_id = user_id
-        self.album_id = album_id
         self.is_public = is_public
         self.id = id
         self.is_fixture = is_fixture
diff --git a/soter/views/picture.py b/soter/views/picture.py
index 5057f59..03705e6 100644
--- a/soter/views/picture.py
+++ b/soter/views/picture.py
@@ -1,3 +1,4 @@
+import hashlib
 import os
 import shutil
 import uuid
@@ -8,10 +9,10 @@ from pyramid.response import FileResponse
 from pyramid.security import authenticated_userid
 from pyramid.view import view_config
 import transaction
-
 import numpy
+
 from soter.models import DBSession
-from soter.models.master import Picture
+from soter.models.master import Picture, Album
 
 
 @view_config(request_method='GET', route_name='upload', permission='Albums')
@@ -33,15 +34,18 @@ def upload(request):
         shutil.copyfileobj(input_file, output_file)
     os.rename(temp_file_path, file_path)
     # Process picture here to get the hash and the exif tags to be added to the database
-    pic = Picture(file_id, str(file_id), uuid.UUID(authenticated_userid(request)), uuid.UUID(album), True, file_id)
+    pic = process_picture(file_path, str(file_id), uuid.UUID(authenticated_userid(request)), file_id, uuid.UUID(album))
     DBSession.add(pic)
     transaction.commit()
     return {'location': file_path}
 
 
-def process_picture(path):
+def process_picture(path, name, user_id, file_id, album_id):
     image = get_image(path)
-    Picture(file_id, str(file_id), uuid.UUID(authenticated_userid(request)), uuid.UUID(album), True, file_id)
+    hash = hashlib.sha512(numpy.array(image)).digest()
+    picture = Picture(name, hash, user_id, True, file_id)
+    picture.albums.append(Album.by_id(album_id))
+    return picture
 
 
 def get_image(path):