Ms Rudd took on that argument and said that might be true "in theory" but that "the reality is very different".
She did not make clear what reality she was referring to, or how she intended to get around that central problem of encrypted communications.
The government supports the use of strong encryption and does not want to ban end-to-end encryption, Ms Rudd says.
Around 7.8 million UK adults used online dating sites in 2016, up from just 100,000 in 2000.
"I know some will argue that it's impossible to have both – that if a system is end-to-end encrypted then it's impossible ever to access the communication," she wrote in a piece for . But the reality is very different." She went on to write that people didn't really want encrypted messaging apps anyway, and that they would prefer to use software with more features.
"Real people often prefer ease of use and a multitude of features to perfect, unbreakable security.
Technology companies say that such a system is impossible.
End-to-end encryption works by ensuring that only the sender and recipient of a message can read it – meaning it would not be possible for tech firms to give government access to specific messages, even if they wanted to.