Do you turn USB Debugging on the instant you get a new phone?

So, someone that steals your phone has access to the data inside?

I seem to remember USB debugging interfering with something else when I had it on on some prior phone. Didn't it do that? Does it still?

I'm all about good heartedly always adding on-topic technical value to the group tribal knowledge, so I spent a lot of effort here to help others.

adb + *sndcpy* example adb + *vysor* example adb + *scrcpy* example

AFAIK, there are no known "problems" that anyone has brought up here which are associated with turning USB debugging on (at least that I know of).

The issue Carlos brought up requires the thief have so many things that it's almost impossible for the scenario he fears to ever actually occur.

Certainly though, you can turn on specific options within "Developer options" that can "interfere" with tools, but as far as anyone has shown in this thread, turning on "USB debugging" within "Developer options" just allows USB debugging (which is what the Android Debug Bridge needs).

Android Debug Bridge (adb)

Certainly billions of Android users are using adb every day, so if it was so dangerous to use, you'd think the net would be filled with horror stories.

BTW, to help document what options I recommend people set, I turned off my Developer options a few times and turned it back on to see what changed.

Obviously each Android version has more & more options, but for my Android

12, here's what I found happened when I turned Developer options off & on.

Listed in order of appearance in my Samsung Android 12 menus...

Turn Developer options = off (the menu after "About phone" disappears). A. Quick settings developer tiles, Wireless debugging goes off B. USB Debugging goes off (if it was on) C. Wireless debugging goes off (if it was on) D. Disable adb authorization timeout goes off (if it was on) E. Enhanced Wi-Fi MAC randomization goes off (if it was on) F. Mobile data always active goes off (if it was on) G. Default USB configuration remains set to what you previously set H. Select mock location app goes off (if it was on)

Here's what I recommend others set for privacy & functionality: (again, listed in the order they appear in the developer options) a. Quick settings developer tiles, Wireless debugging (turn on) [Interestingly its position in the Android tile remains valid!]

Tile position returns! b. USB Debugging (turn on to allow adb connections over USB or Wi-Fi) c. Wireless debugging (turn on to allow adb connections over Wi-Fi) d. Disable adb authorization timeout (turn on but it won't matter much) e. Enhanced Wi-Fi MAC randomization (turn on for privacy per AP) [Note you've also set MAC Address type = Randomized MAC in settings] f. Mobile data always active (turn on for faster Wi-Fi:data switching) g. Default USB configuration (mine is set to "Transferring files") h. Select mock location app (turn on & set to your fake GPS app)

If you use adb every day, like I do to mirror Android (keyboard, mouse, monitor & clipboard & sound) onto the desktop. what other "Developer options" switches do you habitually set in addition to "USB Debugging"?

Mirror Android on the PC

Now I can connect Android over Wi-Fi (I rarely use USB today) to operate a phone from a Windows PC sharing the monitor, mouse, keyboard & clipboard.

adb + *sndcpy* example adb + *vysor* example adb + *scrcpy* example

Clarification of MAC randomization switches & broadcast _nomap SSID issues. Below are the gory details that you only need if you desire basic privacy.

Here's what I recommend others set for privacy & functionality: (again, listed in the order they appear in the developer options) a. Quick settings developer tiles, Wireless debugging (turn on) [Interestingly its position in the Android tile remains valid!]

Tile position returns! b. USB Debugging (turn on to allow adb connections over USB or Wi-Fi) c. Wireless debugging (turn on to allow adb connections over Wi-Fi) d. Disable adb authorization timeout (turn on but it won't matter much) e. Enhanced Wi-Fi MAC randomization (turn on for privacy per AP) [Note you've also set MAC Address type = Randomized MAC in settings] f. Mobile data always active (turn on for faster Wi-Fi:data switching) g. Default USB configuration (mine is set to "Transferring files") [Most phones have the default set to "No data transfer" instead.] h. Select mock location app (turn on & set to your fake GPS app)

As of Android 10+ there's also a new "Wi-Fi scan throttling" option, which is on by default so that it reproduces Android 9 Wi-Fi scan throttling of i. Each foreground app can scan four times in a 2-minute period. (note that this default allows for a burst of scans in a short time) ii. All background apps combined can scan one time in a 30-minute period. <https://betterprogramming.pub/how-to-avoid-wifi-throttling-on-android-devices-494a0cc29dd8>

As always, if you know more than I do about this, please add technical value, clarify existing value, and correct any mistakes I may have made.

Bear in mind everything works together... just as we do on this newsgroup!

The first thing we need to do is clarify what these _two_ switches above do in the later Android versions to allow for MAC randomization not only per AP but also per connection. And I should probably touch on what "static ip" means too.

Note these switches are in my Android 12 but the first one came in Android

10 (as I recall) while the other was added around Android 11 (as I recall).

Note that the very useful "Wireless debugging" tile came only in Android

12, my point being not all these options will be on any older phone.

CAVEAT: For convenience when using adb to connect a Windows (or macOS or Linux) desktop to Android, you often set the IP address to "static", which you can no longer do as easily today from a home router as you used to be able to do whenever you use random MAC addresses! (Ask me how I know this.)

Most people have their home router set to serve addresses out of a block. [x] Use Router as DHCP Server [_] Set Address Reservation per device (see below why this is set to off) [_] Broadcast SSID (this should always be off for privacy reasons)

Note you can no longer "easily" use "Address Reservation" on a typical home router because it usually requires locking to a specific MAC address.

What you do nowadays, instead, is set a "static" IP address on Android: Android12: Settings > Connections > {longpress on} Wi-Fi > {Press on the gear icon for _each_ access point in your settings} Auto reconnect = off (this should _always_ be "off" for privacy reasons) View more > IP settings = static IP address = 192.168.1.4 (set to whatever address you want) MAC address type = Randomized MAC

Note this last setting randomizes the MAC address *per connection*. That is, every time you connect to that SSID, it will have the same (randomized) MAC address. If this is all you set, then you _can_ use Address Reservation in your router; but there's _another_ MAC randomizer!

As per this thread, there is another MAC randomizer for _each_ connection! *Do you turn USB Debugging on the instant you get a new phone?*

When you turn "Developer options" and "USB debugging" as of Android 11+, you also get the option to set the MAC randomization for _each_ connection! Android Settings > Developer options > Enhanced Wi-Fi MAC randomization "Change this phone's MAC address each time it connects to a network that has MAC randomization turned on."

Note you need _both_ MAC-randomization settings in order to accomplish this (and it's suggested you also end your SSID with "_nomap" to complete the privacy steps - which of course, requires you to not broadcast the SSID).

My point in bringing this up to Android, Windows, and wireless newsgroups is to communicate these wonderfully new privacy-based options which never existed before, and which therefore require understanding of what they do.

Note: I'm fully aware that hiding the SSID broadcast is not for _security_ reasons, but many people do not realize hiding it is for _privacy_ reasons!

Specifically, most Android phones driving by your home will upload your GPS location and your unique router BSSID even if you have "_nomap" appended to the SSID (unique because you want your unique-as-possible SSID to stay out of voluminous Internet butterfly/hash tables but that's a separate thing).

Even if Google/Mozilla respect the _nomap on the server side... notice that distinction because it's the whole point that it's _already_ uploaded even if you have "_nomap" appended (where we can forget nowadays about _optout_)... there's no guarantee that the others (e.g., Kismet, Wiggle, etc.) will respect the _nomap optout request).

The solution is to prevent "most" Android phones from even seeing your SSID, which can only be done by hiding the broadcast - where - if someone knows what they're doing, of course _they_ will see your (hidden) SSID - but "most" phones will not _upload_ a hidden ID to the Internet servers, and that's why you hide it.

Of course, once you hide it, then you have to worry about your phone constantly trying to _reconnect_ to it (which shouts out your supposedly unique SSID everywhere you go), so you also need to turn off the auto-reconnection option in Android - which is very easily done.

Here are some representative screenshots illustrating some of the above:

adb + *sndcpy* example adb + *scrcpy* example adb + *vysor* example Android Debug Bridge (adb) Tile position returns! Mirror Android on the PC

There is a short description of every option listed above (and others) here *Explaining every setting in Developer Options* (as of April 2022)

In summary, it all works together, and each release of software allows more privacy options - where this clarifying post is to put some of it together so that you can understand why each specific switch is set and how it has ramifications for setting other things on your PC, router, and phone.