In the newest Rogan episode with Elon musk, Elon states that signal messages can be cracked with about $750,000 of computer time, and it was done on Tucker Carlson's messages arranging the interview with Vladimir Putin.
I don't have the exact location in the 3-hour podcast. Episode #2404.
Spotify
#2404 - Elon Musk
The Joe Rogan Experience · Episode