Schneier on Security

Clive Robinson • November 24, 2025 8:29 AM

@ ALL,

To much security makes things fragile

First off there is the old human sayings of,

1, Accidents happen.
2, And to err is human.

I’m known for saying,

“There is no such thing as accidents, only too little time, knowledge or both.”

As for humans, they are not the only thing to err or fail, systems do it to as many can attest. But untill recently we said that such things were the product of man thus man was the element that was responsible as an easy get out rather than admit “we don’t know enough”.

The design of the voting system was not that of the IACR but another organisation entirely. I would also guess that based on appearances neither the IACR or the voting system organisation had any engineers that had experience in designing intrinsically safe, or fail safe systems, or they got over ridden.

Because there are two fundamental rules for such design,

1, Design to have no single point of failure.
2, Design to fail safe.

If we look at what happened both rules were apparently broken.

The article says,

“Per the association’s bylaws, three members of the election committee act as independent trustees. To prevent two of them from colluding to cook the results, each trustee holds a third of the cryptographic key material needed to decrypt results.”

And thereby each of the trustee becomes intrinsically,

“A single point of failure”

Whilst the second point of “fail safe” can be problematic with some security protocols and the supporting Cryptographic based systems. The first rule becomes even more critical and should always hold.

The use of an M of N shared secret protocol would have stopped this particular “fail unsafe” issue.

As I’ve previously noted,

“At the very least the associations rules should have allowed for human frailty. Aircraft fall out of the sky, ships sink, and motor vehicles crash many on more than a daily basis, likewise sickness and unfortunate health events take many more, often quite unexpectedly.”

These things may be unpalatable, but we do recognise they happen all the time.

Clive Robinson • November 24, 2025 2:53 PM

@ KC, ALL,

With regards the comments of “Ben Adida” –the implementor of the Helios Voting system used–, he links to the NYT article, the last two paragraphs of which are,

“Though errors are rare in Helios’s work with the cryptology group, said Mr. Adida, the software engineer, the case showed that there can be trade-offs in designing and using hyper-secure systems.

“It turns out that managing keys and managing secret keys is the hardest part of this — even among the world’s best cryptographers,” he said.”

The article and what has subsequently been said in the MSM and trade press and blogs etc still does not say who was responsible for the design / usage of the Helios system.

So we are left with the question as to who made the choice of operating the vote in an extremely fragile way.

That is,

1, IACR dictating the terms of Helios use.
2, Helios pushing an overly fragile design on the IACR.

Not that it really matters as far as the vote or subsequent actions are concerned “the omelet has been served”.

However the fact that it’s being said the IACR are shifting to an M of N of 2,3… Is actually not the correct decision if they want to stop “collusion between two officers” (the stated aim). Because the difference between 2 and 3 is only one not two or more.

What they need is a minimum of two times the collusion margin of officers plus one if a majority decision is required.

So if my maths is upto the task 😉 they need a 3 of 5 system. That is five officers need a key share.

But something for all system implementors to consider, a point that I’ve made here from time to time,

“Technical systems are rarely the solution for social issues.”

It there is one social issue that causes more strife in humanity than anything else it’s “Fairness Systems” of which “voting systems” is the most frequently seen cause of arguments to see serious consideration.

Clive Robinson • November 25, 2025 1:02 AM

@ Gary Sturgess,

With regards,

“if the intent of a 3-split is to ensure that no two trustees can collude, doesn’t that make it impossible to switch to a 2 out of 3?”

Simple answer “yes”.

The longer answer is what sort of collusion are you looking at preventing, as there are two basic types,

1, To stop fake results being accepted.
2, To stop honest results being rejected.

The worst case is the second where both colluders have to actively show their hand.

To prevent that you need more “election officers”(5) as I detail in my post above yours,

https://www.schneier.com/blog/archives/2025/11/iacr-nullifies-election-because-of-lost-decryption-key.html/#comment-450122