The Glorious Gridiron Cryptowars Imagined by a 1970s NSA Employee

Football coach holding a playbook covered in binary code.
Photo illustration by Slate. Photo by Jonathan Newton/The Washington Post via Getty Images.

This weekend’s big game is a chance for Americans to enjoy the best of football: offensive skill, defensive dedication, and impressive backup dancing during halftime.

But what you won’t see is any codebreaking—presumably to the disappointment of the National Security Agency employee who once predicted (sort of) that cryptography would dominate football by 1999.

From 1974 to 1997, the NSA published a staff magazine called Cryptolog that was intended to help the expanding staff at the agency exchange ideas with one another. One editor described it as “a mix of technical, expository, philosophical, futuristic, argumentative and historical articles.” The NSA declassified all of the issues in 2013, though some content was blacked out in the released copies, still sensitive after a quarter-century.

Alongside commentary about the Soviet Union and some complicated-looking puzzles, the January 1976 issue contained a tongue-in-cheek article titled “Football & Cryptology.” The author’s name is still classified, but given that headline, it’s reasonable to assume that whoever wrote it was an NSA codebreaker.

The piece starts off straightforwardly enough. Our anonymous author is interested in what could happen to football if radios were embedded in helmets to allow coaches to communicate with their players. (So far, so good!) Obviously coaches would want to eavesdrop on one another’s radio signals, the NSA codebreaker writes, which in turn would make communication security a coaching priority. And the best way to ensure security over a public channel, like radio waves across a football field, is to scramble the communications using encryption.

The NSA commentator follows this train of thought to its extreme conclusion and makes a series of increasingly elaborate predictions for how this gridiron cryptowar would play out.

Within three years of helmet radio receivers, the author imagines, most teams will hire mathematicians to make and break new ciphers. One team will pioneer the no-huddle offense after adopting uniforms that are a “combination of medieval armor and space suit” and can deliver oxygen, Gatorade, and pure adrenaline to players. Within 10 years, “the cryptologic aspects of football [will] become at least as important as the play itself,” and cryptologists will command salaries on par with the players. Breakthroughs in neuroscience will lead to connecting receivers directly into players’ brains. Within 25 years, “the whole point of the game [will be] cryptanalysis,” and unpredictable human players will be entirely replaced by robots. Newspaper sports pages will replace athletic commentary with cryptanalytic commentary. The yearly NFL draft will pick mathematicians, rather than players, for contracts running to tens of millions of dollars.

Today, the article is ridiculous (and funny), but not in the way the writer likely intended. In 1976, encryption technology was impractical. Any two people wanting to exchange an encrypted message had to agree beforehand on the secret key they would use to encrypt and decrypt their data, and strong ciphers required expensive machines. Encryption was used mostly by governments and large banks whose secrecy needs warranted the necessary massive investment. At the time, the absurdity of this article was in applying the day-to-day business of the NSA to the realm of sports. Why would football need to spend the same resources on advanced technology that the government spent on national security?

A few months after the crypto-football article, two computer scientists published a paper that described a new method of encryption in which the two parties wouldn’t have to exchange their secret key ahead of time. This public-key encryption, together with faster computers, enabled the creation of secure internet browsing. If used correctly, public-key encryption is very unlikely to be broken even by dedicated codebreakers. It worried the NSA so much that the agency tried to intimidate the academic researchers who worked on it. It failed.

So by the time the NFL finally allowed helmet radio receivers for quarterbacks in 1994, anyone could use NSA-grade encryption. Football teams didn’t need codebreakers, although they still worried about communication security. In 2008, the NFL claimed its headset system employed “268 million different encryption codes” for scrambling communications, though what exactly that meant isn’t clear. Malicious hackers have also started targeting all sorts of organizations, including professional sports teams, to steal data and disrupt operations. The investment necessary for information security has plummeted while the need for it has increased. Now, it seems obvious that the NFL might care about radio encryption, but it’s laughable that it would need to hire world-class cryptographers.

Coaches in football and plenty of other sports have employed basic encryption methods for decades, disguising play calls in cryptic hand signals and printed signs held on the sidelines. The 2007 Patriots videotape spying scandal highlighted the weaknesses of this system and pushed the NFL to allow defensive players to don headsets the following year.

Because headset technology is similar to that used for other wireless communications like cellphones, frequency jammers could theoretically interfere with signals. Angry coaches have made plenty of accusations over the years after game-time communications problems, though no tampering has ever been proven. The NFL switched its radio transmission system from analog to digital in 2012, which it claimed improved sound quality in the headsets. This switch also cut down on frequency mishaps, like the case of the San Francisco 49ers headsets picking up pilot chatter.

Although robot football and high-dollar math drafts haven’t quite materialized, encryption has become even more ubiquitous than our cryptologist predicted, securing not just play calls in football but everything from text messages to bank transactions. Cryptography may have spread beyond the walls of the NSA, but there’s no chance it will push football out of the cultural spotlight anytime soon.