Spoiler: READ FIRST

This is created to keep out nosy brothers from your 3DS activity and life, remember, you have the right to keep your privacy intact!

Spoiler

This is just posting isn't it?

1. Open Luma (Press Select while powering on)
2. Scroll down until you see PIN Lock.
3. Set the PIN lock using A until you get to your desired PIN length.
4. Press Start.
5. Now you should see Luma asking you to set the PIN.
6. After that's done, go and re-enter your PIN.
7. Profit.

To remove them if you forgot, please refer to @CPG 's guide in this sub-forum.

 

[KleinesSinchen]

The 3ds will long be back in my possession already before that replacement battery arrives. Also I'll be sure to thank the kind person for the free replacement battery when it does arrive. Also i have my device set to default boot a garbage payload that will black screen. Only way to get it to boot successfully is by pressing the right button combination.

Sadly this doesn't offer any more protection than the Luma3DS pin. More like security by obscurity.
Taking the battery out frequently is a hassle because of the screws and setting the date/time (yes, I know Luma has ntp functions now).

that's not the point. the point is so if you have kids theyre less likely to accidentally brick ur 3ds or something

That is pretty much all one can achieve with the pin.
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A modification of B9S loading boot.firm from NAND first ignoring the SD when a CTRNAND copy is available would be more secure (requiring ntrboot to bypass). Such a modification however fails to be safe for the console.

 

[Deleted member 668561]

The 3ds will long be back in my possession already before that replacement battery arrives. Also I'll be sure to thank the kind person for the free replacement battery when it does arrive. Also i have my device set to default boot a garbage payload that will black screen. Only way to get it to boot successfully is by pressing the right button combination.

Good luck locating your stolen 3ds, it'll be sold for money, it's not hard to wipe a 3ds

 

[KleinesSinchen]

Good luck locating your stolen 3ds, it'll be sold for money, it's not hard to wipe a 3ds

To be fair no protection will give you your device back if stolen. A phone can maybe be located if some vendor-specific total surveillance module is on it (same for some laptops).

But else: What does it help to have your device unusable by a thief? They might still sell parts or the whole thing for parts. I have seen countless phones and tablets with "forgot my Google account/password, factory reset protection active" for sale. (Not that I suspect all these to be stolen -- forgotten account data is very common)

There should be no private or even intimate data on a 3DS so protection against reading it out is not really needed either.
=========

Anyway: Rather than just pondering and discussing the topic, I went ahead and recompiled B9S today to give NAND boot the preference. This seems to work as intended. Without the pin I cannot access any payloads, the SD is fully ignored in the boot process.

This protection with a custom boot9strap.firm offers a little more security but ultimately is not gonna stop a determined attacker from using the 3DS. It just comes close to this thread title: It will prevent nosy people (siblings?) from casually using your console against your will.

 

[Deleted member 668561]

To be fair no protection will give you your device back if stolen. A phone can maybe be located if some vendor-specific total surveillance module is on it (same for some laptops).

But else: What does it help to have your device unusable by a thief? They might still sell parts or the whole thing for parts. I have seen countless phones and tablets with "forgot my Google account/password, factory reset protection active" for sale. (Not that I suspect all these to be stolen -- forgotten account data is very common)

There should be no private or even intimate data on a 3DS so protection against reading it out is not really needed either.
=========

Anyway: Rather than just pondering and discussing the topic, I went ahead and recompiled B9S today to give NAND boot the preference. This seems to work as intended. Without the pin I cannot access any payloads, the SD is fully ignored in the boot process.

This protection with a custom boot9strap.firm offers a little more security but ultimately is not gonna stop a determined attacker from using the 3DS. It just comes close to this thread title: It will prevent nosy people (siblings?) from casually using your console against your will.

Ntrboot is unpatchable

 

[Flaire]

What would you have on a 3ds that you wpuld have to put a passcode on it?

 

[RaptorDMG]

What would you have on a 3ds that you wpuld have to put a passcode on it?

Games that you don't want other people tampering with

 

[Flaire]

Games that you don't want other people tampering with

Thats true, wait couldn't it be possible to make a app lock type program for the 3ds?

 

[KleinesSinchen]

Thats true, wait couldn't it be possible to make a app lock type program for the 3ds?

The 3DS will probably never be a universally usable computer. Theoretically almost everything could be done on it since we have full system control milliseconds after boot – but who should do it?

There is Parental Pin that can limit access (can be trivially bypassed with master code generator https://mkey.salthax.org/) and Luma3DS pin (can be trivially bypassed by deleting the pin file on the SD – unless you do what I did a few posts above; in this case the attacker needs an ntrboot cart to bypass).

 

[Flaire]

The 3DS will probably never be a universally usable computer. Theoretically almost everything could be done on it since we have full system control milliseconds after boot – but who should do it?

There is Parental Pin that can limit access (can be trivially bypassed with master code generator https://mkey.salthax.org/) and Luma3DS pin (can be trivially bypassed by deleting the pin file on the SD – unless you do what I did a few posts above; in this case the attacker needs an ntrboot cart to bypass).

I have a old 3ds i dont ntrboot works on it

 

[jeffyTheHomebrewer]

I have a old 3ds i dont ntrboot works on it

NTRBoot works on ALL 3DS family systems.

 

[Flaire]

NTRBoot works on ALL 3DS family systems.

Eh either way I have save backups.

 

[Deleted member 560739]

wow,i never knew about this
thanks

 

[Flaire]

wow,i never knew about this
thanks

Theres loads of things that can be done on the 3ds, which is why the 3ds homebrew community is so broad.

 

[Deleted member 560739]

dont i know it lol

 

[Flaire]

dont i know it lol

I'd definately try it, especially since Nintendo isnt making anything for the system anymore.

 

[Deleted member 560739]

I'd definately try it, especially since Nintendo isnt making anything for the system anymore.

i actually made some homebrew a couple weeks ago
developing for the 3ds is definitely a challenge but its a fun one

 

[Flaire]

i actually made some homebrew a couple weeks ago
developing for the 3ds is definitely a challenge but its a fun one

And the community is really helpful, if you ever have a question somebody will always have a answer.

 

[Deleted member 560739]

And the community is really helpful, if you ever have a question somebody will always have a answer.

my several hours of googling problems ive had definitely proves that

 

[Flaire]

my several hours of googling problems ive had definitely proves that

You're better of asking or searching on this forum

 

[alivebacon]

Ntrboot is unpatchable

You need one of a list of flashcarts to use that, not everyone can obtain an eligible cart. Also that's brick protection, it won't matter if they're just gonna sell it for parts anyway.

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What would you have on a 3ds that you wpuld have to put a passcode on it?

Reply I made earlier to the exact same question:

that's not the point. the point is so if you have kids theyre less likely to accidentally brick ur 3ds or something