Why bitcoins storing on a smartphone are considered vulnerable?

Question

Let's suppose, someone stores all their bitcoins in an Android or iOS wallet.

• he/she never stores a seed on the phone
• he/she uses different addresses for change
• wallet and gadget are password protected
• the smartphone is always kept only by the owner
• there's no connection to iCloud, DropBox, etc
• potentially dangerous apps are not installed on the phone

If you follow all of the above rules, then why is it generally accepted that storing cryptocurrency in a mobile wallet is considered unsafe?

Answer 1

Why bitcoins storing on a smartphone are considered vulnerable?

Its a perception based on their experience. Lot of things depend on user, type of smart phone, usage etc.

Two major things that are different on smartphone compared to desktop:

1. Its easy to run virtual machines on desktop. Few things exist for Android but I have not tried yet: https://www.xda-developers.com/vmos-lets-you-run-a-virtual-android-environment-on-your-phone/

2. Smartphone normally comes with lot of things you don't find in desktops. SIM & Network, GPS, Camera, Microphone etc. Neither good for privacy nor security. Although there are few people and companies who sell mobile phones without some of these: https://www.vice.com/en/article/wjwbmm/inside-the-phone-company-secretly-run-by-drug-traffickers

Some of the best practices mentioned in the question are not followed by users. Last point about apps is very important and if you can keep a separate smartphone with less apps then it can be considered safer. Other important things are processor, kernel, ROM etc.

Answer 2

If attackers hack into this smartphone and obtain the private key of your bitcoin wallet, your bitcoins will be stolen.

The higher risk than other devices of smartphones is:

1. Your smartphone may be lost or very easily stolen from your pocket, because it has a small size and always with you outside.
2. Your smartphone can be easily intentionally hacked remotely with its rich communication capabilities (LTE, WiFi, BT) and hypothetical backdoor or loaded from store under the guise of programs (games) trojans.