(12) United States Patent (10) Patent N0.: US 8,123,114 B2

US008123114B2

(12) United States Patent (10) Patent N0.: US 8,123,114 B2 Chaum (45) Date of Patent: Feb. 28, 2012

(54) HIDDEN-CODE VOTING AND MARKING (56) References Cited SYSTEMS

U.S. PATENT DOCUMENTS

(76) Inventor: David Chaum, 811611112111 Oaks, CA (US) 6,726,090 Bl * 4/2004 Kargel ““““““““““““““ " 235751 7,021,539 B2 * 4/2006 HureWitZ 235/386

( * ) Notice: Subject to any disclaimer, the term ofthis 7,516,891 B2 * 4/2009 Chaum .... .. 235/386

patent is extended or adjusted under 35 \(élattlhm BI er .. . . . . . ..

U80 1546)) by 145 days‘ 2003/0158775 A1 * 8/2003 Chaum 705/12 2005/0269406 A1 * 12/2005 Neff ...... .. 235/386

(21) APP1- NO-I 12/385,633 2008/0272194 A1 * 11/2008 Chaum ........ .. 235/386 ' 2008/0281682 A1 * 11/2008 Euchner et a1. ............... .. 705/12

Flled: Apl‘. 14, * Cited examiner

(65) Prior Publication Data Primary Examiner * Michael G Lee

US 2009/0308922 A1 Dec. 17, 2009 Assistant Examiner i SueZu Ellis

(74) Attorney, Agent, or Firm * Clark & Brody Related US. Application Data

(63) Continuation-in-part of application No. (57) ABSTRACT PCT/US2009/001339> ?led on Mar- 3: 2009- An improved paper ballot voting system alloWs voters to

(60) Provisional application No. 61/033,179, ?led on Mar. Verify that their ballots are Correctly Counted and Prm/ide 3, 2008, provisional application NO_ 61/088,046, ?led substantiating evidence if they are not. Codes are revealed to on Aug 12, 2008_ voters by the act of marking the ballot during voting and

voters can check that these codes are posted. If these codes are (51) IIlt- Cl- not posted as marked, voters can make the codes they

G06F 11/00 (2006-01) obtained public. These codes made public by voters can be G0 7C 13/00 (2006-01) compared against codes that Were cryptographically commit

(52) US. Cl. ......................... .. 235/51; 235/50 A; 705/12 ted to in advance of the election, Ifthe codes from voters do (58) Field of Classi?cation Search ................ .. 235/386, in fact match codes committed to, evidence of incorrectness

235/51, 50 R, 50 A, 50 B, 54 E; 283/5; 705/12; ofthe vote tallying is provided. 434/306

See application ?le for complete search history. 2 Claims, 19 Drawing Sheets

US. Patent Feb. 28,2012 Sheet 1 0119 US 8,123,114 B2

1 10

@ Commit to codes ’\-12O

Voting Phase

132\5\ Allow voters 34 Print ballots to learn codes

for positions marked

136%‘, Cast ballots Audit printing \_§/~13a

a Q ~ . a u . u s o o Q a s u - a . - s 0 a - o Q v i Q a o n a u a u . . n u . o a a a I Q e Q a » v a u a v v a - a Q u u 0'

Voter Checking Phase

Validate/invalidate f 143 Post voted codes proffered Codes

(preferably not revealing correspondence between vote and code)

_ .

_ .

_ .

_ .

_ .

_ .

. . . . . .y...".......n..-.....[.......................-.....a

Optionally audit some physical ballots “*

160


um “115W gm


% Oi?cial Ballot O 55": Official Ballot O

1. President 1. President

C) Joe Smith I Joe Smith

CD Barbara Jones @ arbara Jones

2. Treasurer 2. Treasurer

G Mary McMoon @119 ary McMoon 6 Art Kelley Art Kelley

' . . . . . , . . 1 . . . . . . . . . . . ........................................................... F | 9 6A Fig 6B

355": Official Ballot Q Of?cial Ballot O

1. President 1. President

Joe Smith Joe Smith

@ arbara Jones @ arbara Jones

2. Treasurer 2. Treasurer

ary McMoon E2) ary McMoon Art Kelley Art Kelley

............................. P .......................... .. .

a 5 .B???i?éi

Fig 6C Fig 6D


US. Patent Feb . 28, 2012 Sheet 6 0f 19 US 8,123,114 B2

Print positions Print each position Print each position . with an with two

ditterently than . . unpredictabie unpredictable other areas

code codes

1001/ 1020/ \1041 People mark Positions marked

People mark the forms, hiding by people hide one the forms the codes from code and deveiop

marked positions the other

1003 ~/ 1022 J \t 043

The unmarked Read the Read the . . unpredictabie unpredictable positions are

codes from each codes from each sensed . . . .

unmarked position position / '\

1005/ 1024/ \tO45

The marked Report the codes Repon the Codes positions are from the unmarked . .

. . from the positions sensed positions

/ j/ '\\ 1007 1026 ' 1047

009 028 1049 V / Y / \ v

Check that a“ Check that Check that positions are accounted for, marked or unmarked

printed codes

reported codes are consistent with the

reported codes are consistent with the

printed codes

Fig 10 Fig Fig 106



Formulate real and Formulate real and dummy inks dummy inks

/ /

1 ‘/ ‘I’ 1 / 1r

Print real and dummy Print real and dummy inks on forms as inks on forms as

symbol forground and symbol forground and background background

/ r

1303/ 1322/

Repeat for each use +- Repeat for each use +

r /

1305/ 1324/

Provide printed forms Pmv'de forms. after . markmg with

and developing pens . . developing pens to for markmg by user

user

// J/ 1307 1309 \ 1326 1328 \

Allow inspection of Allow inspection of forms once marked forms by user at least dummy ink has after marked dummy

become ink has become indistinguishable from distinguishable from

marked real ink marked real ink

Fig 13A Fig 138

US. Patent Feb. 28, 2012 Sheet 9 0f 19

1. President

O Joe Smith

C) Barbara Jones

2. Treasurer

Q Mary McMoon C) Art Kelley

3. How many marks above?

O 1

CD 2

1. President

® Joe Smith ® Barbara Jones

2. Treasurer

® Mary McMoon @ Art Kelley 3. How many marks above?

Fig 14A Fig 14c

1 . President

@ Joe Smith ® Barbara Jones

2. Treasurer

® Mary McMoon ® Art Kelley 3. How many marks above?

® 1 ® 2

1. President

XY C) Joe Smith

CA C) Barbara Jones

2. Treasurer

RB o Mary McMoon NQ @ Art Kelley

3. How many marks above?

XZ CD 1

TS CD 2

Fig 145 Fig 140

US 8,123,114 B2

US. Patent Feb. 28, 2012

Voter allowed to mark ballot and "mark count"

contest 1501/

V

Ballot casting begins

1 503

1505/

Device counts marks on ballot

Device reads any mark count mark

1509

1511

counted marks

mark count

Sheet 10 0f 19

Display or print count and mark countcode

Voter option to obtain ballot

Voter allowed to check mark

1519

Ballot cast

Fig. 15

US 8,123,114 B2

1513 J/


1820

KY

1620

1610

1630

Fig. 18 Fig. 16

US. Patent Feb. 28, 2012 Sheet 12 0f 19

Provide voters with choice of pens from pool that make subtly

' different marks 1701 /

V

Voters to choose pens substantially at random and

, make marks

Voters to return pens to pen pool

/1707 Marks later made with different pens

would be distinguishable

Fig. 17A

US 8,123,114 B2

Provide voters with pens that make subtly

different marks _

over time or use \ 1720

Voters to use pens to make marks

\ 1722

V

Marks made later with pen would be distinguishable

A

Fig. 175 \ 1724

US. Patent

1901

Feb. 28, 2012

Election begins Election begins

Voter allowed to mark ballot

I

Voter allowed to mark ballot with fixative in ink

1903/

Voter allowed to cast ballot

Voter allowed to cast ballot

Ballot coated with material

Ballot developed but developement

prevented by fixative where

marked n

1909

V

Audit begins

1

17

Audit begins

Ballot potentially inspected to detect marks 1911

\ made after coating

Ballot potentially inspected to detect marks made after development -

Fig. 19A Fig. 198

Sheet 13 0f 19 US 8,123,114 B2

1 920

\ 1922

\1924

\ 1926

1928

/193O


2130a "\,

2140a”\ 2150 f“

\:U__ l PET 2170a N 21701) ~/

2180 2110a\ 1/‘

2190 / Q6 2160


2201 Voter choice segment begin

2203

Voter makes

unpredictable choice

V V

Form is marked Form is marked with voter choice with voter choice

2205 ~/“ "L" R ,k 2251

V V

Voter choice "|_" Voter choice "R" is obtained by is obtained by

» system system / 2207 \2253

L i Crypto receipt Crypto receipt inciuding voter including voter choice "L" is choice "R" is

A printed and printed and ,\ 2209 / provided to voter provided to voter 2255

Voter choice segment end Fig. 22

2275



1. ....................................... 1, C) CD

2. ....................................... .. (I) (I)

3. ...................................... 1. C) CD

Flg 24A

US. Patent Feb. 28, 2012

Create codes substantially at

2501 \ randonrn

Encrypt each code with a substantially

2503 '\ ~/ random key

Publish the encrypted codes

Fig. 25A

Sheet 19 0f 19 US 8,123,114 B2

2520

Repeat per voter

Allow voter to till next position on

form

V

Allow voter to choose one code

to reveal

Publish the decrypted codes

Fig. 258

Documents

(12) United States Patent (10) Patent N0.: US 8,123,114 B2