>United States officials used a secret backchannel to communicate with Iran in recent days, sending messages via Swiss intermediaries
Using a means that can be found in wikipedia is NOT a 'secret backchannel'.
Coincidence MSM is using the word?
>https://en.wikipedia.org/wiki/Iran–Switzerland_relations
Switzerland has had a consulate in Tehran since 1919 which was raised to the status of embassy in 1936 and also represents the interests of the United States in the Iranian capital Tehran.