Hi Alaeddine,
Currently, ArcSDE doesn't support columns with identity property set to True. Tables/Feature classes with this property cannot be edited in ArcMap or registered as versioned.
When attempting to create non-versioned edits in ArcMap you will receive an error similar to:
"Database Row Change: An unexpected failure occured.
Underlying DBMS error[Microsoft sql server Native Client 10.0: Cannot insert explicit value for identity column in table 'tableName' when IDENTITY_INSERT is set to OFF.][..tableName]."