Close. The real story is that that the design of the s-boxes in DES appeared a bit strange to the crypto community, and there were rumors that the NSA had been

Close. The real story is that that the design of the s-boxes in DES appeared a bit strange to the crypto community, and there were rumors that the NSA had been involved in selecting the values. Foul play was suspected. It turns out that the values in the DES s-boxes were very resistant to differential cryptanalysis, much more than they would have been if they were selected randomly. Either the NSA knew this technique back in the 70s or the IBM researchers figured it out and agreed to keep it secret (both claims have been made); it was not until independent discovery in the 90s that we all learned why the s-boxes had those specific values.