Hello,
I have an old-ish smartphone, a Huawei Rio L03 GX8. I want to give it away, and I’ve done a factory reset. However, after reading articles such as this one ( [fr_most15.pdf (cam.ac.uk)](https://www.cl.cam.ac.uk/~rja14/Papers/fr_most15.pdf) ) I am worried about my data not being safe. Can anyone weigh in on this? I have heard that factory reset ensures that the data is gone for good, but this article seems to claim otherwise.
This doc seems outdated. I haven’t read it thoroughly though. They bought secondhand phones in 2014 with Android versions v2.3.x to v4.3.
4.4 came out in 2014. Maybe further research appropriate to your model version would help?
I don’t think the person receiving your used phone have that much knowledge or time on their hand to perform forensics and retrieve all deleted data.