Yesterday the California Secretary of State released the reports of three source code study teams that analyzed the source code of e-voting systems from Diebold, Hart InterCivic, and Sequoia.

• Diebold systems
• Hart InterCivic systems
• Sequoia systems

All three reports found many serious vulnerabilities. It seems likely that computer viruses could be constructed that could infect any of the three systems, spread between voting machines, and steal votes on the infected machines. All three systems use central tabulators (machines at election headquarters that accumulate ballots and report election results) that can be penetrated without great effort.

It’s hard to convey the magnitude of the problems in a short blog post. You really have read through the reports – the shortest one is 78 pages – to appreciate the sheer volume and diversity of severe vulnerabilities.

It is interesting (at least to me as a computer security guy) to see how often the three companies made similar mistakes. They misuse cryptography in the same ways: using fixed unchangeable keys, using ciphers in ECB mode, using a cyclic redundancy code for data integrity, and so on. Their central tabulators use poorly protected database software. Their code suffers from buffer overflows, integer overflow errors, and format string vulnerabilities. They store votes in a way that compromises the secret ballot.

Some of these are problems that the vendors claimed to have fixed years ago. For example, Diebold claimed (p. 11) in 2003 that its use of hard-coded passwords was “resolved in subsequent versions of the software”. Yet the current version still uses at least two hard-coded passwords – one is “diebold” (report, p. 46) and another is the eight-byte sequence 1,2,3,4,5,6,7,8 (report, p. 45).

Similarly, Diebold in 2003 ridiculed (p. 6) the idea that their software could suffer from buffer overflows: “Unlike a Web server or other Internet enabled applications, the code is not vulnerable to most ‘buffer overflow attacks’ to which the authors [Kohno et al.] refer. This form of attack is almost entirely inapplicable to our application. In the limited number of cases in which it would apply, we have taken the steps necessary to ensure correctness.” Yet the California source code study found several buffer overflow vulnerabilities in Diebold’s systems (e.g., issues 5.1.6, 5.2.3 (“multiple buffer overflows”), and 5.2.18 in the report).

As far as I can tell, major news outlets haven’t taken much notice of these reports. That in itself may be the most eloquent commentary on the state of e-voting: reports of huge security holes in e-voting systems are barely even newsworthy any more.

I wrote Monday about the California Secretary of State’s partial release of report from the state’s e-voting study. Four subteams submitted reports to the Secretary, but as yet only the “red team” and accessibility teams’ reports have been released. The other two sets of reports, from the source code review and documentation review teams, are still being withheld.

The Secretary even held a public hearing on Monday about the study, without having released all of the reports. This has led to a certain amount of confusion, as many press reports and editorials (e.g. the Mercury News editorial) about the study seem to assume that the full evaluation results have been reported. The vendors and some county election officials have encouraged this misimpression – some have even criticized the study for failing to consider issues that are almost certainly addressed in the missing reports.

With the Secretary having until Friday to decide whether to decertify any e-voting systems for the February 2008 primary election, the obvious question arises: Why is the Secretary withholding the other reports?

Here’s the official explanation, from the Secretary’s site:

The document review teams and source code review teams submitted their reports on schedule. Their reports will be posted as soon as the Secretary of State ensures the reports do not inadvertently disclose security-sensitive information.

This explanation is hard to credit. The study teams were already tasked to separate their reports into a public body and a private appendix, with sensitive exploit-oriented details put in the private appendix that would go only to the Secretary and the affected vendor. Surely the study teams are much better qualified to determine the security implications of releasing a particular detail than the lawyers in the Secretary’s office are.

More likely, the Secretary is worried about the political implications of releasing the reports. Given this, it seems likely that the withheld reports are even more damning than the ones released so far.

If the red team reports, which reported multiple vulnerabilities of the most serious kind, are the good news, how bad must the bad news be?

UPDATE (2:45 PM EDT, August 2): The source code review reports are now up on the Secretary of State’s site. They’re voluminous so I won’t be commenting on them immediately. I’ll post my reactions tomorrow.

A major study of three e-voting systems, commissioned by the California Secretary of State’s office, reported Friday that all three had multiple serious vulnerabilities.

The study examined systems from Diebold, Hart InterCivic, and Sequoia; each system included a touch-screen machine, an optical-scan machine, and the associated backend control and tabulation machine. Each system was studied by three teams: a “red team” did a hands-on study of the machines, a “source code team” examined the software source code for the system, and a “documentation team” examined documents associated with the system and its certification. (An additional team studied the accessibility of the three systems – an important topic but beyond the scope of this post.)

(I did not participate in the study. An early press release from the state listed me as a participant but that was premature. I ultimately had to withdraw before the study began, due to a scheduling issue.)

So far only the red team (and accessibility) reports have been released, which makes one wonder what is in the remaining reports. Here are the reports so far:

• Red team overview
• Red team report on Diebold systems
• Red team report on Hart Intercivic systems
• Red team report on Sequoia systems
• Accessibility team report

The bottom-line paragraph from the red team overview says this (section 6.4):

The red teams demonstrated that the security mechanisms provided for all systems analyzed were inadequate to ensure accuracy and integrity of the election results and of the systems that provide those results.

The red teams all reported having inadequate time to fully plumb the systems’ vulnerabilities (section 4.0):

The short time allocated to this study has several implications. The key one is that the results presented in this study should be seen as a “lower bound”; all team members felt that they lacked sufficient time to conduct a thorough examination, and consequently may have missed other serious vulnerabilities. In particular, Abbott’s team [which studied the Diebold and Hart systems] reported that it believed it was close to finding several other problems, but stopped in order to prepare and deliver the required reports on time. These unexplored avenues are presented in the reports, so that others may pursue them. Vigna’s and Kemmerer’s team [which studied the Sequoia system] also reported that they were confident further testing would reveal additional security issues.

Despite the limited time, the teams found ways to breach the physical security of all three systems using only “ordinary objects” (presumably paper clips, coins, pencil erasers, and the like); they found ways to modify or overwrite the basic control software in all three voting machines; and they were able to penetrate the backend tabulator system and manipulate election records.

The source code and documentation studies have not yet been released. To my knowledge, the state has not given a reason for the delay in releasing these reports.

The California Secretary of State reportedly has until Friday to decide whether to allow these systems to be used in the state’s February 2008 primary election.

[UPDATE: A public hearing on the study is being webcast live at 10:00 AM Pacific today.]

By now there is overwhelming evidence that today’s paperless computer-based voting technologies have such serious security and reliability problems that we should not be using them. Computers can’t do the job by themselves; but what role should they play in voting?

It’s tempting to eliminate computers entirely, returning to old-fashioned paper voting, but I think this is a mistake. Paper has an important role, as I’ll describe below, but paper systems are subject to well-known problems such as ballot-box stuffing and chain voting, as well as other user-interface and logistical challenges.

Security does require some role for paper. Each vote must be recorded in a manner that is directly verified by the voter. And the system must be software-independent, meaning that its accuracy cannot rely on the correct functioning of any software system. Today’s paperless e-voting systems satisfy neither requirement, and the only practical way to meet the requirements is to use paper.

The proper role for computers, then, is to backstop the paper system, to improve it. What we want is not a computerized voting system, but a computer-augmented one.

This mindset changes how we think about the role of computers. Instead of trying to make computers do everything, we will look instead for weaknesses and gaps in the paper system, and ask how computers can plug them.

There are two main ways computers can help. The first is in helping voters cast their votes. Computers can check for errors in ballots, for example by detecting an invalid ballot while the voter is still in a position to fix it. Computers can present the ballot in audio format for the blind or illiterate, or in multiple languages. (Of course, badly designed computer interfaces can do harm, so we have to be careful.) There must be a voter-verified paper record at the end of the vote-casting process, but computers, used correctly, can help voters create and validate that record, by acting as ballot-marking devices or as scanners to help voters spot mismarked ballots.

The second way computers can help is by improving security. Usually the e-voting security debate is about how to keep computers from making security too much worse than it was before. Given the design of today’s e-voting systems, this is appropriate – just bringing these systems up to the level of security and reliability in (say) the Xbox and Wii game consoles would be nice. Even in a computer-augmented system, we’ll need to do a better job of vetting the computers’ design – if a job is worth doing with a computer, it’s worth doing correctly.

But once we adopt the mindset of augmenting a paper-based system, security looks less like a problem and more like an opportunity. We can look for the security weaknesses of paper-based systems, and ask how computers can help to address them. For example, paper-based systems are subject to ballot-box stuffing – how can computers reduce this risk?

Surprisingly, the designs of current e-voting technologies, even the ones with paper trails, don’t do all they can to compensate for the weaknesses of paper. For example, the current systems I’ve seen keep electronic records that are subject to straightforward post-election tampering. Researchers have studied approaches to this problem, but as far as I know none are used in practice.

In future posts, we’ll discuss design ideas for computer-augmented voting.