lllllllllllllllllllllllllllllllllllll||ll|Illllllllllllllllllllllllllllllll US005533

United States Patent 1191 Force et al.

123A

Patent Number: 61] 5,533,123 [45] Date of Patent: Jul. 2, 1996

[54] PROGRAMMABLE DISTRIBUTED 4,926,388 5/1990 Kunita etal. ......................... .. 365/244 PERSONAL SECURITY 4,933,898 6/1990 Gilberg 6131. ....... .. 365/53

5,027,397 6/1991 Double et a1. . .... .. 380/4

[75] Inventors: Gordon Force’ San Jose’ Calif‘; 5,053,992 10/1991 Gilberg et a1. . ...... .. 365/53 D- l)avis7 Arlington’ Tex; 5,083,293 1/1992 Gilberg 61 al. ................... .. 365/189.01

. _ 5,117,457 5/1992 Comerford etal. . ..................... .. 380/3 Richard L. Duncan, Bedford, Tex., 5 159 629 10,1992 D M al 38014 Thomas M Norcross Arlin ton Tex' ’ ’ Ou- e at ' "

_ - _’ g 1 -’ 5,185,717 2/1993 Mon ................. .. . 365/52

Mwhael J~ ShayArhngwmTeXé 5,353,350 10/1994 Unsworth et a1. ........................ .. 380/3 Tlmothy A. Short, Duncanville, Tex. _ _ _ _

Primary Exammer-Dav1d C. C3111 [73] Assignee: National Semiconductor Corporation, [57] ABSTRACT

Santa Clara, Calif. The present invention is embodied in a Secured Processing

[21] APPL NO; 267788 Unit (SPU) chip, a microprocessor designed especially‘ for secure data processlng. By integraung keys, encrypuon/

[22] Filed: Jun. 28, 1994 decryption engines and algorithms in the SPU, the entire

[51] Int. Cl.6 . . . . . . . . . . . . . . . . . . . . . . . .. H04L 9/00 Sammy PTOFBSS 1S rend‘ired portable 3“? ets‘ly dlsmbmed

4_ across physical boundaries. The lnvention 18 based on the [52] UIS' Cl‘ """"""" " 380, ’ 380,52 orchestration of three interrelated systems: (i) detectors, [58] Field Of Search ...................................... .. 380/3, 4, 52 which alert thg SpU to the existence’ and help Characterize

_ the nature, of a security attack; (ii) ?lters, which correlate the [56] References Cited data from the various detectors, weighing the severity of the

UIS_ PATENT DOCUMENTS attack against the risk to the SPU’s integrity, both to its _ secret data and to the design itself; and (111) responses, which

4,446,475 5/1984 Gercekcl et al. ....................... .. 357/40 are Countermaasures’ calculated by the ?lters to be most

E1105‘; 6‘ a1- """"""""" " appropriate under the circumstances, to deal with the attack ’ ’ .eune """""" " or attacks present. The present invention, with wide capa

4,598,17O 7/1986 Piosenka et al. . 178/2208 b.1. . all hr f h d ?l d 4,691,350 9/1987 Kleijne etal. 380/3 ‘19’ m 1 6e 0 t 6 me???’ tars an IGSPOHSCS’ 4,764,959 8/1988 Watanabe 6161. 380/4 allows ?1 great degree of ?CXIPIhPY for Programmmg a? 4,783,801 11/1988 Kalll? ...................... .. 380/3 approp??te 19v91 9f S?CllnIy/pohcy 111“) an sPU-b?sed 39911 4,807,284 2/1989 Kleijne . . . . . . . . . . . . .. 380/3 Cation

4,811,288 3/1989 Kleijne et al. 365/52 4,860,351 8/1989 Weingart ................................... ._ 380/3 14 Claims, 19 Drawing Sheets

.

‘POWER ISOLATION ' 12 36

' _ MICRO

CONTROLLER

GENERAL PURPOSE

32 |/0 PORT

EXTERNAL 33 BUS INTERFACE

9/

ROM

RESET

20 SILICON FlREWALL

US. Patent Jul. 2, 1996 Sheet 2 of 19 5,533,123

23 VOUT VPP 24

191 22 vnn POWER , L ______ ___A_P_WF_?QD______ 40

21 VBAT swncumc ~ ------ "SEE-P ---- --41

ClRCUlT ALARM - ---------------- ~38

PWRGD 114 '27

105 1,102 28

)__ CHIP_ START PWRGD PWRUP A26

vccPwoP 10s COUNTER DLY__PWRGD 112

VREF ' RESET 115 Cm

cm SET_PWOP 4§} 25

110 109 108

cm START

PWRDN VCCPUD '*' 107 COUNTER ' s11$1TZPowN

‘RESET

104 /’ ‘

111 CLR_PWOP Q03

13

FIG. 2

US. Patent Jul. 2, 1996 Sheet 3 0f 19 5,533,123

710

/

INPUT 716 OUTPUT '/ 747/‘

A \712

FIG. 3

cLocT<\714 720

/ 722 724 / /

/ \ / 732 726 727 754

A /\ F 728 729 ' IG' 4

\ 730

740 /

742

744 7 1 46 756

D Q t>—i-— > ,754

/ 752

758 / “748

FIG. 5 H50

US. Patent Jul. 2, 1996 Sheet 6 0f 19 5,533,123

RTCLK RIPPLE COUNTER

RQLEQVER _ _

"32 ‘is

SYNC BLOCK

CLOCK__RTC CLEARRTC

303 \_

25

305 304

BUS INTERFACE CTR AND DECODER

INTERNAL 1O BUS

FIG. 8

U.S. Patent Jul. 2, 1996 Sheet 7 0f 19 5,533,123

802 ,L

806 ,805 DISABLE AccEss

/ NO" TO THE KEY EXECUTE OTHER

FIRMWARE PROGRAMS

, 810 INVER'HNG ALL THE BITS OF THE KEY

\ . s12

CHANGE THE KEY lNVERSlON STATUS BIT

,/814 ENABLE AccEss TO THE KEY

FIG. 9

US. Patent Jul. 2, 1996 Sheet 8 0f 19 5,533,123

CLOCK

US. Patent Jul. 2, 1996 Sheet 9 of 19 5,533,123

\/864- V866

l

856\ /865 /857

855 V

854 \

853 ll A l /

4 1 A

/ A350 852 l

0 1 2 3 4 5 0 1 2 3 4 5

862/

868 /

FIG. 11

US. Patent Jul. 2, 1996 Sheet 10 of 19 5,533,123

906 907 905

902 903 904

FIG. 12

)7/20 925 926 930

/ & 9/27 928 i 929 931

US. Patent

§MONOTONICITY TEST;

{CLOCK OROSS~OIIEOI<I

Jul. 2, 1996 Sheet 11 0f 19 5,533,123

START 55‘

READ BACK -/552 LAST RTC READINO

SIONAL “560A SECURITY -»—I PROBLEM -

RECORD PRESENT I 554 TIME AS

RTc READINO

‘ 5 PERFORM FIXED M 55 TASK OF I<NOwN SYSCLK DURATION

RECORD ‘A56 PRESENT TIME

AS END READINO

SIGNAL ‘A59 SEOLIRITY PROBLEM

I

C 5:3 558

FIG. 140

US. Patent Jul. 2, 1996 Sheet 12 of 19

( START >451

/252 ;

POWER UP, INITIALIZE SPU

PERFORM I MODIFICAITON 0515011011

PERFORM MODIFICATTON DETECTION

INORMAL OPERATING STATE;

5,533,123

IMANUFACTURING STATE}

EXECUTE ONLY COMMANDS

THAT RESTRICT‘ ACCESS TO SECRET DATA

ZEROIZE ALL SECRET DATA

AREAS. USE DEFAULT

CONFIGURATION. \ 256

ENABLE MANUFACTURING TEST AND SET CONFIGURATTON COMMANDS.

\ 263

PERFORM MANUFACTURING

TESTS

\ 264

LOAD SECRET DATA,

STORE MODIFICATTON

CODE \ 265

SET VRT=I

257 FIG. 14b END

US. Patent Jul. 2, 1996

351% START )

Sheet 13 0f 19

FIG. 15

READ BACK OUTPUT PORT REGISTERS

,/ 354

SAVE IN TEMPORARY STORAGE

./ 355

MOVE TEST NON-SECRET

DATA

./ 356

I

READ BACK OUTPUT PORT REGISTERS

3/ 357

MOVE NEXT PART OF SECRET

DATA

TRANSFER DATA ON BUS

CONVENTION ALLY

ABORT, SIGNAL

SECURITY PROBLEM

END

362

361

5,533,123

-/ 553

US. Patent

FIG. 16

Jul. 2, 1996

START 4m

I

SET l/O PORT BTT x To 1

Sheet 14 0f 19

/402

,

READ l/O PORT BIT x

SECURITY PROBLEM

ABORT, SIGNAL

END 407

V404

/ 406

5,533,123

US. Patent Jul. 2, 1996 Sheet 15 0f 19 5,533,123

940 START

‘

SET vALUES »I/ 942 OF THE LIMIT

PARAMETERS

,/ 948 PROCESS

vALIO COMMAND

CALCULATE / 950 NUMBER OF

INVALID COMMANDS/UNIT TTME

SIGNAL /954 A FIRST LIMIT

SECURITY PROBLEM

SIGNAL /958 A SECOND LIMIT SECURITY PROBLEM

SIGNAL /962 THIRD LIMIT 7

SECURITY PROBLEM

SIGNAL 1/966 FOURTH LIMIT

SECURITY PROBLEM

US. Patent

HARDWARE

Jul. 2, 1996 Sheet 16 0f 19 5,533,123

INTERRUPT FIRMWARE HARDWARE/ FIRMWARE

‘?

,/463

/ 459

RETURN FROM‘ INTERRUPT S‘GNAL

\

C4: 458

FIG. 18

US. Patent

FIG. 190

FIG. 19b

FIG. 19c

Jul. 2, 1996 Sheet 17 of 19 5,533,123

501

j / 502

D0 v\\ A0 :’

505 j 504

Db I ® 505

7/ D01

5/06 508 509 510

DC2 FC1

507 /

D03

I/\ A I \

<9} 7 R0 3/ 512 L _ _ _ - =

515 A _

<6; Re 514

US. Patent Jul. 2, 1996 Sheet 18 of 19 5,533,123

1026 /

MESSAGE TO Y USER, TRANSFER TO OTHER CARD Row

{ . POWER . T

6) STATE; S ATE} 1027 N

FIG. 200

U.S. Patent

MESSAGE To’ USER, NOT TO‘ DO IT AGAIN

Jul. 2, 1996

__@/1040

@1038 DISABLE

PERMANENTLY \1036

1

LM 1037

Sheet 19 0f 19 5,533,123

FIG. 20:] FIG. 20b

KEY TO FIG. 20

FIG. 20b