Voting by mail might be safer, but is it secure?

April 22, 2020

Avi Rubin, Information Security Institute’s Technical Director, gives opinion on the security threats of voting by posting  mail in the upcoming elections.

Voting by postal mail is an increasingly attractive option for the upcoming November election. While “vote by mail” systems have several drawbacks, in the face of COVID-19 and the need to keep a safe distance among people, this option may be the least unattractive. It is important to note that a state that planned on having a poll site election may not be able to automatically and easily switch over to a mail-in system overnight. There are many logistical issues that need to be addressed. One of the challenges faced by election officials is that at the moment, it is not clear if the pandemic will subside before November. Given that it could take months to switch from the current plans to a mail-in system, state officials would have to start planning the change now, without knowing for sure if they will need to switch.

“Vote by mail” provides opportunities for vote selling and voter coercion. For example, a spouse or employer may have the ability to pressure someone to vote a certain way. Furthermore, the postal system is not immune to tampering. Still, wide scale wholesale fraud is probably more difficult to achieve in a mail-in system than in many other systems such as fully electronic or Internet based ones. In the current crisis we face, we may need to give up on the perfect for the sake of the good (or the least bad) and switch the country over to mail-in voting for this upcoming election. We still have over 6 months, and hopefully that is enough time for states to take the steps that they need to achieve this change. Several states already vote by mail, and those states’ officials can provide guidance to states who want to switch over for this coming election.

There is a risk that if many states switch over to vote by mail, that they will make the switch permanent. It would be a shame if future elections eliminate poll site paper-based voting because of this one-time necessary adjustment we have to make this year. However, we should focus right now on November, 2020. We’ll have plenty of time to worry about future elections. Hopefully, we will be rid of this pandemic and will be able to focus on providing the best possible election system in 2022 and 2024.


In a special “Coronavirus Conversation” on TEDxMidatlantic, ISI’s Avi Rubin explains how the pandemic may affect our elections, and helps us to understand the kinds of trade-offs that may be necessary in this difficult election year. Click here to watch the interview.


JHU Information Security Institute