Extension:SecurePasswords/password history table

mysql> describe password_history; +--+--+--+-+-+---+ +--+--+--+-+-+---+ +--+--+--+-+-+---+
 * Field       | Type             | Null | Key | Default | Extra |
 * ph_user     | int(10) unsigned | NO   | PRI | NULL    |       |
 * ph_password | mediumblob       | NO   |     | NULL    |       |
 * ph_timestamp | varbinary(14)   | NO   | PRI |         |       |