MARY LOUISE KELLY, HOST:
Now the latest clue to a puzzle that has stumped amateur and professional cryptographers for three decades. The puzzle is Kryptos. It is a sculpture commissioned by the CIA to grace one of the courtyards at the agency's Langley headquarters. It's a curving copper wall with a secret code embedded across four panels. The first three have been decoded, but that last one still eludes even the pros of the CIA and the National Security Agency, which is why the sculptor - Jim Sanborn - has decided to drop another clue. Jim Sanborn, welcome back to ALL THINGS CONSIDERED.
JIM SANBORN: Thanks for having me.
KELLY: Why give us a new clue now?
SANBORN: Well, it is very close - within days - to when I actually developed that 97-character string. The dedication ceremony is actually not until November, but obviously prior to the dedication, I had to come up with the final clue section. And that's why I'm doing it now, basically.
KELLY: The 30-year anniversary.
SANBORN: The 30th anniversary.
KELLY: Thirtieth anniversary. OK. And what is the new clue?
SANBORN: The new clue is the word northeast.
KELLY: When and if it is finally cracked, what is the puzzle? What is the mystery that will be revealed?
SANBORN: It's a 97-character phrase. And that phrase is in itself a riddle. It's mysterious. It's going to lead to something else. It's not going to be finished when it's decoded.
KELLY: So what you're telling me is when somebody finally deciphers what this fourth panel actually says, it's posing a riddle that then we'll have to all go out and start solving.
SANBORN: That's right.
KELLY: And I should remind - you have dangled two clues before. You gave us the clue Berlin, also clock.
SANBORN: Yes. I gave Berlin once and then clock a second time. And this is the third and to be sure final clue.
KELLY: Oh, really? No more? If we don't get it now, that's it?
SANBORN: Yeah. If you don't get it now, that's it. I'm 74. I do have a health challenge. And I'm not necessarily giving out shortly.
KELLY: I hope not. I hope not.
SANBORN: I really do want Kryptos to remain secret - the plain text, the final section of Kryptos, I would prefer for it to remain secret indefinitely.
KELLY: Oh, you hope nobody ever solves it?
SANBORN: Every artwork, I think - I mean, I would think that every artist would aspire to making an artwork that is not transient. It's a permanent visual, auditory, conceptual statement. And I did Kryptos with all those things in mind. And one - as an artist, one would prefer to have that piece continue giving rather than have it understood right off the bat and then more or less ignored. And so this has lived way beyond all of my expectations, you know, at 30 years in retaining a secret that it has, and that's the magic.
KELLY: We should note there's an irony here. You are not a professional code writer or code breaker. You're not a mathematician. When I've interviewed you before, you told me you're pretty lousy at math.
SANBORN: I am lousy at math to the point where I consider myself to be anathamath (ph). Now, perhaps being an artist, I have an advantage in that I can employ methods that don't have anything to do with mathematics.
KELLY: And I know the fourth panel, it's short, right? It's 97 characters, which means if you are trying to look for a pattern that might help you crack this code, there's just not that much to look at.
SANBORN: Frequency of certain letters that correspond to the English language don't really work well when you have a short passage. And so I don't know that I really at that time thought about it, but it certainly has been the case. Let's just say that if there are codes - if all codes could be cracked, then we'd be in pretty bad shape because all national secrets, all kinds of things would be available to just about anyone. And so let's all hope that there are indecipherable codes out there because they're often saving our lives. And so Kryptos obviously isn't that relevant, but it's hopefully doing something. It's certainly employing a lot of minds.
KELLY: Jim Sanborn, thank you.
SANBORN: You're welcome.
KELLY: The sculptor Jim Sanborn talking there about the latest clue he is dangling to help us crack the mystery of Kryptos. Transcript provided by NPR, Copyright NPR.