Abstract:
An automated teller machine includes a processor on motherboard with BIOS on ROM which allows operation of hard disk via interface. The disk has at least one normal partition but also includes a hidden security partition not accessible under normal system control. Data relating thereto can be encoded for security reasons.

Description:
BACKGROUND OF THE INVENTION 
     The invention relates to data security arrangements. 
     When handling data, for example in a self service terminal such as an Automated Teller Machine (ATM), access needs to be restricted. When data is stored on a rotatable storage medium (e.g. a hard disk) there is a need to reduce the risk of unauthorized access. 
     The present invention is concerned with assisting in providing such security. 
     SUMMARY OF THE INVENTION 
     According to the invention there is provided a security method for a rotatable storage device characterized by providing a hidden security partition in the device, and wherein information on the position of the partition is stored on the device in such a manner as to prevent access by normal system operation. 
     In a preferred embodiment the method is employed in operating a self service terminal. 
     Further according to the invention there is provided a rotatable storage device having a storage sector for storing information on at least one storage partition and characterized by a hidden security partition located thereon and inaccessible during normal system operation. 
     In a preferred embodiment the device is employed in a self service terminal. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will now be described by way of example with reference to the accompanying drawings in which: 
     FIG. 1 shows a known ATM system; 
     FIG. 2 shows the control system for the FIG. 1 arrangement; 
     FIG. 3 shows the processor control aspect of an ATM in more detail; 
     FIG. 4 shows a typical partition table sector associated with the hard disk of FIG. 3; 
     FIG. 5 shows the inventive aspect of the hidden partition; and 
     FIG. 6 shows the store and access mechanisms respectively for the hidden partition. 
    
    
     DETAILED DESCRIPTION 
     In the typical ATM arrangement of FIG. 1, the ATM  10  is enclosed within a cabinet  11  and has customer utilization arrangements such as a magnetic card input slot  12 , a display screen  14 , a keypad  16 , a cash delivery slot  18  and a balance and/or payout slip delivery slot  19 . 
     The control system for the ATM  10  is shown in FIG. 2 in which a processor  22  is connected to receive input from the card reader  12  and keypad  16 , to control the display  14  and to control a cash counting and delivery system  26  connected to the cash delivery slot  18 . A paper slip delivery system  20  is provided for dispensing a printed payout slip, account balance or the like, connected to the delivery slot  19 . The processor is connected by a connector  24  to the central authorization system of the financial institution operating the ATM  10 . 
     In the FIG. 2 arrangement it is necessary to access, handle and store data and the processor arrangement  22  is shown in more detail in FIG.  3 . Typically the processor will include a number of components to allow the system to operate. The heart of the processor will be a microprocessor chip  30  mounted on a motherboard  32 . Input and output information/control will pass via interface  34  and driving the display will be achieved by display driver  35 . Memory chips  33  (RAM) provide immediate data handling capability. 
     Other memory chips  36  (ROM) provide operational information in permanent form. A disk interface  37  provides connection to a hard disk  38  through its disk controller ( not shown separately). 
     The devices except the hard disk  38  are all shown mounted on the motherboard for simplicity, but some devices may be situated on separate cards mounted on the motherboard. 
     A hard disk  38  provides large scale storage for the computer and will carry software to run the system as well as data regarding transactions and the like. The motherboard BIOS (Basic Input Output System) allows the system to operate correctly including hard disk operation. This BIOS is accessed at the commencement of the boot up program and the BIOS is typically held in the ROM  35  (and possibly partially in the disk controller  37 ). 
     For the computer to bootstrap (boot) after internal self checks, the ROM BIOS checks the hard drive at a specific location for ‘system files’ and reads data stored on the disk&#39;s first sector and copies this to RAM to allow the stored system files to be loaded into RAM. 
     During the computer system operation, when data is to be read from a file, the operating system instructs the hard disk controller to move the drive head to the drive&#39;s file allocation table (FAT) to determine where the start of that file begins so that the correct file can be accessed. 
     Security of information on ATMs is paramount to both the Financial Institutions and the customer in the street. To protect this information system/procedures require to be in place to restrict/control access to the software and data present on the ATM&#39;s hard drive  38 . This includes restricting system boot up if certain security criterion are not met. 
     During the normal software initialization of a hard disk, partitions are laid down in the first sector of a disk, known as the Partition Table Sector. Within this first sector there is a defined area called the Partition Table where up to four 16 byte partition entries can be written. This information details where each partition is located on the disk, how big it is and whether the partition can be used to boot the system. The Motherboard BIOS within the system indexes into this Partition Table to find the boot partition and then loads the boot sector code pointed to by the boot partition and subsequently loads the system software. A typical Partition Table Sector from a disk is shown in FIG.  4 . 
     The Partition Table Sector has a storage capacity of 16×32 (512 bytes). The bootstrap code is at the beginning (commencing at address  00000000 ) with Partition Table entries towards the end of the sector. Each Partition Table entry requires 16 bytes of data. As illustrated the first Partition Table entry (shown in bold) commences as address  000001 B 0 . Up to four partitions may be required on large disks and each 16 byte entry can follow on from each other up to the end of the sector. Thereafter bytes ‘ 55  AA’ denote to the computer BIOS that the Partition Table contains valid data. 
     In the present invention we have now included a Security Partition above the area where the standard partition entry information is placed, utilizing space within the Partition Table Sector, so that it will not be recognized by the normal operating system as a hidden partition. 
     The Security Partition data details the whereabouts of the special hidden partition on the disk. Since Operating Systems currently only use the defined Partition Table area to detail partition information the Security Partition would be unknown and therefore inaccessible to other users. The Security Partition details can also be encoded such that it was not obvious that the data was describing a hidden disk partition. This hidden partition can then contain proprietary code and information used to implement secure access to the system software and data. 
     FIG. 5 again shows a partition table but it now includes hidden Security Partition data within the Partition Table Sector. The normal partition information is again written at address  000001 B 0 . However, unused space above the area recognized as giving partition information is employed for security partition data. In this example the offset address  00000160  is used and data indicative of the partition is stored (shows as XX bytes). Only knowledge of the offset of the hidden Security Partition data entry within the Partition Table Sector and the encoding algorithm would allow the hidden partition to be found. 
     Hence to set up the Security Partition the appropriate partition defining information can be laid down at the offset address by means of the steps shown in FIG. 6 a . Access can be made using the steps shown in FIG. 6 b , which is outside the accessibility of the normal operating system. 
     During installation of the ATM build suite the Partition Table Sector would be written with the encoded hidden Security Partition. Only the manufacturer&#39;s proprietary software/firmware would have knowledge of the encoding algorithm and the offset address of the hidden partition data. The software load of data onto the disk could include loading any security information into the hidden partition on the disk. Access to which would only be achieved through special proprietary software and firmware routines. The motherboard BIOS could also be modified to include special routines to access the hidden partition to validate security data before allowing the system to boot. Hence this additional security measure restricts/controls access to the software and data on the hard disk and includes restricting system boot up if certain security requirements are not met. 
     In the arrangement shown in FIG. 3 the disk  38  is an IDU disk. In a variation, for use with an SCSI disk, the disk interface  37  is replaced by an SCSI controller.