Secrecy News

Cryptographer Adi Shamir Prevented from Attending NSA History Conference

In this email message to colleagues, Israeli cryptographer Adi Shamir recounts the difficulties he faced in getting a visa to attend the 2013 Cryptologic History Symposium sponsored by the National Security Agency. Adi Shamir is the “S” in the RSA public-key algorithm and is “one of the finest cryptologists in the world today,” according to historian David Kahn. The NSA Symposium begins tomorrow. For the reasons described below, Dr. Shamir will not be there.

From: Adi Shamir

Date: October 15, 2013 12:16:28 AM EDT


Subject: A personal apology

The purpose of this email is to explain why I will not be able to attend the forthcoming meeting of the History of Cryptology conference, even though I submitted a paper which was formally accepted. As an active participant in the exciting developments in academic cryptography in the last 35 years, I thought that it would be a wonderful opportunity to meet all of you, but unfortunately the US bureaucracy has made this impossible.

The story is too long to describe in detail, so I will only provide its main highlights here. I planned to visit the US for several months, in order to attend the Crypto 2013 conference, the History of Cryptology conference, and to visit several universities and research institutes in between in order to meet colleagues and give scientific lectures. To do all of these, I needed a new J1 visa, and I filed the visa application at the beginning of June, two and a half months before my planned departure to the Crypto conference in mid August. I applied so early since it was really important for me to attend the Crypto conference – I was one of the founders of this flagship annual academic event (I actually gave the opening talk in the first session of the first meeting of this conference in 1981) and I did my best to attend all its meetings in the last 32 years.

To make a long story short, after applying some pressure and pulling a lot of strings, I finally got the visa stamped in my passport on September 30-th, exactly four months after filing my application, and way beyond the requested start date of my visit. I was lucky in some sense, since on the next day the US government went into shutdown, and I have no idea how this could have affected my case. Needless to say, the long uncertainty had put all my travel plans (flights, accommodations, lecture commitments, etc) into total disarray.

It turns out that I am not alone, and many foreign scientists are now facing the same situation. Here is what the president of the Weizmann Institute of Science (where I work in Israel) wrote in July 2013 to the US Ambassador in Israel:

“I’m allowing myself to write you again, on the same topic, and related to the major difficulties the scientists of the Weizmann Institute of Science are experiencing in order to get Visa to the US. In my humble opinion, we are heading toward a disaster, and I have heard many people, among them our top scientists, saying that they are not willing anymore to visit the US, and collaborate with American scientists, because of the difficulties. It is clear that scientists have been singled out, since I hear that other ‘simple citizen’, do get their visa in a short time.”

Even the president of the US National Academy of Science (of which I am a member) tried to intervene, without results. He was very sympathetic, writing to me at some stage:

“Dear Professor Shamir

I have been hoping, day by day, that your visa had come through. It is very disappointing to receive your latest report. We continue to try by seeking extra attention from the U. S. Department of State, which has the sole authority in these matters. As you know, the officers of the Department of State in embassies around the world also have much authority. I am personally very sympathetic and hopeful that your efforts and patience will still yield results but also realize that this episode has been very trying. We hope to hear of a last-minute success.

Yours sincerely, Ralph J. Cicerone”

What does all of this have to do with the History of Cryptology conference? In January 2013 I submitted a paper titled “The Cryptology of John Nash From a Modern Perspective” to the conference, and a short time afterwards I was told by the organizers that it was accepted. In July 2013 I told the NSA-affiliated conference organizers that I was having some problems in getting my visa, and gently asked whether they could do something about it. Always eager to help, the NSA people leaped into action, and immediately sent me a short email written with a lot of tact:

“The trouble you are having is regrettable…Sorry you won’t be able to come to our conference. We have submitted our program and did not include you on it.”

I must admit that in my 35 years of attending many conferences, it had never happened to me that an accepted paper of mine was yanked out from the official program in such a unilateral way. However, since I never try to go to places where I do not feel wanted, I decided to inform MIT that a window had become available in my busy schedule. They immediately invited me to visit them on October 17 and 18, and to give a major lecture during my visit. Naturally, I accepted their gracious invitation.

The final twist in this saga happened a few days ago, when out of the blue I was suddenly reinvited by the conference organizers to attend the event and to present my paper. However, this is too late now, since I am already fully committed to my visit to MIT.

So what is the bottom line of this whole unhappy episode? Clearly, no one in the US is trying to see the big picture, and the heavy handed visa bureaucracy you have created seems to be collapsing under its own weight. This is not a security issue – I have been to the US close to a hundred times so far (including some multi-year visits), and had never overstayed my visas. In addition, the number of terrorists among the members of the US National Academy of Science is rather small. As a friend of the US I am deeply worried that if you continue to delay visas in such a way, the only thing you will achieve is to alienate many world-famous foreign scientists, forcing them to increase their cooperation with European or Chinese scientists whose countries roll the red carpet for such visits. Is this really in the US best interest?

Best personal wishes, and apologies for not being able to meet you in person,

Adi Shamir

22 thoughts on “Cryptographer Adi Shamir Prevented from Attending NSA History Conference

    1. Loved the understated topic description, with just that last phrase hinting at the import of the work. Sweet. 🙂

    1. The story about the “German guy” does not count. He clearly tried to violate the conditions of the VWP program and therefore he was rightfully and correctly denied entry. His account of the happenings is dubious at best and contains insults of the immigration officers and other signs of pure arrogance. What he experienced is not a general problem (except for people ignorant of or willfully ignoring the rules of Visa and VWP).

      1. He “clearly” violated?


        The accusation by the immigration officials is a laughable construction. He is a hobby musician. He was offered a warm meal for one of his shows. Your condemnation of a victim of what seems to be rejection quota reeks of deference.

        1. He is a professional musician (sells cds) not a hobby musician.

          I doubt he hadn’t a few cds with him to sell them there where he played.

          His business is not just doing free shows. He also planned for photoshooting.

          He was clearly there on business and lied about it.

      2. @Hans

        I think you are mistaken. Maybe you used Google Translate? I read the translation Google Translate provides, and it does not give you the full picture.

        For his visit he does not need a visa, his German passport is enough. See

        If you really think that playing 4 concerts for free and another one for a meal is a business trip, you should maybe change your line of business 😉

        In my humble opinion the blog post does not contain insults of the immigration officers, he just describes their behaviour.

        The arrogance displayed was solely on the part of the immigration officers, a sort of arrogance that is also reflected in your comment.


  1. And another german, a writer:

    He already had a visa but he was not allowed to enter USA. He was invited to give a lecture (speech) on a congress of German Philologists. His “crime” seemed to be that he was a co-initiator of an public letter of protest against german surveillance and the non-acting of the german government against Prism.

  2. I feel like it would be a reasonable course of action to react by holding such conferences in countries with less, let’s say, questionable procedures regarding visitors from foreign countries, and do so with ostentation. Of course, the scientific community is small by comparison, but the first step is usually taken by a small number of people, isn’t it?

  3. All the 5 eyes alliance countries are pulling this stunt. Canada has been denying climate scientists, and the US as well. Time to write off all those countries as totalitarian and have academic conferences in countries such as Ecuador or Brazil, or even Japan.

  4. If a person has been to a breeding ground of terrorism (Yemen) – then there is a 100% chance of being suspected. This story is unfortunate, but the keywords are Yemen, Pakistan….etc .. If a person cannot take care to answer questions properly, and has raised a red flag by visiting those countries, you know it takes two hands to clap.

    1. Where did you see those keywords exactly? Also, this is happening to many many scientists from many countries not in the Visa waiver program, and solely due to the nature of their scientific work. There is no common sense used here: no regard for their history in visits to the US or even to their importance to US national security, in some cases.

  5. As a European, I commend the US on their considerable efforts to foster scientific research collaboration between Israel and the EU.

  6. This is not new. I know scientists from various countries–in Asia, Europe, middle east–who applied up to a year in advance, who had also lived in the US, visited many times, and were denied visas without any reason. Of course the stupidity of doing this for such a high profile visitor as Adi Shamir is beyond belief.

  7. I am a US citizen and resident who has intermittently helped organize IEEE and IEC international standards meetings for over 30 years. For the last few years I have avoided placing those meetings in the US, due to similar visa problems and, in one case, having a delegate turned back at his point of entry after an overseas flight. The short-sightedness of such draconian policies is apparent.

  8. My egoistic side says a big THANK YOU for fostering the scientific cooperation elsewhere 😉 Other people in other countries (I, too, do not live in the US) definitely benefit from the US actively driving the international scientific community away.

    Nobody really needs to go to the US. I myself have not been there since the US suspended their constitution and stopped being a state under the rule of law (Rechtsstaat). Of course, it sometimes is really annoying, if you miss an interesting conference, because it is there. But honestly, I don’t want to pay a price similar to the German guy posted by K. F. Katlewski above (that story is really horrifying) – just to visit a conference.

    My altruistic side – a human feeling with other humans in the world – is of course very sad to witness a society in decay there. But then, that’s the ordinary development of civilisations: ascension, prime-age, decay – already described by Polybius more than 2000 years ago. The US does not have a democracy, anymore; it definitely looks more like an ochlocracy.

  9. I can certainly understand why he was not admitted. Pure and simple: Our national security must be protected.

  10. A regrettable story, of course. But why was he applying for a J-1 visa? His Turing Award and obvious contributions to science and being part of the NAS, etc, should easily get him a O-1 visa. I can more easily believe he was mistaken when he wrote that, and actually meant that he was applying for an extension of an O-1 visa!…

  11. I wonder what would happen if all foreign schientists simply boycotted meetings in the the US, or better: Refused to visit the US at all. Initially, this would undoubtedly constitute a disadvantage for any of them – but in the long run, it might work the other way round.

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