Locked SIM card

[Nonno]

Can anyone tell me how to go to my plan or my account or ???  and determine if my SIM card is locked?  If it is not, how do I lock it.

Reason:  

Security

A SIM card offers security for both the user's data and his or her calls. The cards can be locked, meaning that only someone who has the correct personal identification number (PIN) can use the card. If the phone is stolen, the thief cannot use a locked SIM or get any information off of it without the PIN.

Thanks for your help!

[GinYVR]

@SavannahlavoieYou will need to wait for a response from the Moderators.. however since in your other messages you have indicated you already have a message in the queue.. you just have to be patient as it is first come first serve and no point jeopardizing your spot in the queue. Alternatively if you are in a hurry, maybe you should just grab another prepaid provider's SIM card to use on your trip?

[Savannahlavoie]

I set it myself but now to unset it I need a PUK ? I’m just wondering if you have that ? I’ve been trying all day long to get ahold of someone but I can’t 

[Luddite · Accepted solution]

@Nonno I have an iPhone 5. Some suggestions:

a) do not set a SIM lock; an iPhone will not store any of your information on the SIM

b) set the time to lock screen for 5 minutes; it's a pain to keep entering that 4 digit PIN

c) go to Settings >> Cellular and scroll to the bottom to be sure Wi-Fi assist is turned OFF, otherwise you will use cellular data even while connected to wifi; while on that screen be sure Find iPhone is turned ON

d) unless you plan to backup the phone manually to a computer using iTunes go to Settings >> tap your name at the top of the screen >> iCloud scroll down to iCloud Backup and turn ON so that if you ever lose the phone you can easily restore everything onto a new phone.

Welcome to Public Mobile and Apple! 

[Korth]

iPhone will let you use a 4-digit numeric PIN.  It's good enough.  Every time you pull the phone out of your pocket or turn it on (for any reason other than to just glance at the time or see who called) then you enter the PIN, takes half a second.  It'll automatically turn itself "off" and lock again after left idling for a minute, partly to save battery and partly for security.

A longer alphanumeric/keyboard password or other more exotic password is more secure.  But takes longer to enter, it's inconvenient.  iPhone 5 will allow 3 failed attempts then force a 5 minute delay before the next guess, then 10 minutes, 20 minutes, an hour, etc.  Realistically, someone methodically brute forcing through all possible combinations has about ~0.05% chance of correctly guessing your PIN within the first hour plus ~0.05% chance of correctly guessing it within the first day and each day afterwards, and the phone will automatically firmware lock ("brick") itself after a total of 50 failed access attempts (0.5% chance of correct guess) - it can then only be unlocked at an Apple store (along with receipt or other proof of ownership).

The SIM card also imposes another lockout called PUC or PUK, too many failed access attempts (5? or 10?) will lock the SIM card (and attached service) until you are issued a PUK code from the PM mods.  This is intended to halt service to a stolen device while preventing all but the most technically proficient thieves from brute forcing onwards to the point of gaining access or bricking the device.

The iPhone has user settings to adjust screen-off delay time, self-lock time, maximum number of access attempts, etc, you can tighten or loosen the security to your preferences within these parameters.  Or you can disable it entirely (not recommended).  Or you can download/install countless iOS apps which somehow change the password mechanism or otherwise improve security.

Most people are far more worried about the phone itself than the information it contains (which can be conveniently synced off-device, with a computer or the Cloud) or the cellular subscription (which only an idiot would ever attempt to steal, because it leads the cops right to him).  Most thieves, too, think in these terms - iPhone 5 is an older device now, but some of the fancy new premium phones cost $1000+.

[Anonymous]

@Nonno, it all depends on how much you use the phone.  If you are using it a few times an hour, you might want a longer time before locking.  If you are using it a few times a day, then might as well have a short delay before locking.   Also remember that if the phone rings, you should be able to answer without entering the password.

[Nonno]

Many thanks to the community members.

I got a lot of help and learned a ton . . . much appreciated!

As most of you probably guessed, I am a tech Newbie . . .  an old guy, dragged screaming and kicking into the tech age.

It appears as if the advice to change PIN comes off an old post on NET.

So . . .  it now appears as if there are 2 steps I want to follow:

Put password on phone (an inherited IPhone 5)

And   be prepared to cancel phone plan ASAP if it goes missing.

So now the question becomes . . .  what are recommendations for timing of Password on phone.  Seems like it could be a hassle if one chooses too short a time and a security concern if chooses too long of a time.

Any recommendations here?

Thanks again.

[Korth]

Agreed with @will13am ... using a found or stolen phone (after it has been reported as lost or stolen) is raw stupidity.

An active cellphone is a continuous transmitter.  The carriers always know where the phone is by radiolocation from the closest towers - with surprising accuracy in areas with multiple overlapping coverage.  Even an inactive (but powered) cellphone pings the network often - at least once every two minutes to keep the clock time sync, necessary because cellphone signal multiplexing is largely based on extremely accurate digital timing.  And don't forget any Wi-Fi, internet, or GPS tracking which might be activated while the device is in use.

There's also apps - like Find My iPhone, Device Manager, and Find My Device - which let owners track their misplaced devices.

My understanding is that once a device IMEI has been registered as Lost/Stolen (or an E911 call is placed from it) then law enforcement has access to any device location information they need.  Though I could be mistaken, or actual legal machinery could operate differently from carrier to carrier or region to region.

[will13am]

SIM lock is pretty weak sauce these days as a security measure.  TBH, only a fool of a thief would take your SIM and start using your service.  It is like wearing a sign on your body saying I have stolen somebody's cellular service.  The network logs would lead right to the perpetrator's front door. 

Instead of worrying about the tiny piece of plastic, think of the phone and the value of the content.  That is what needs to be secured as already mentioned.  Use a strong password or long PIN code.

[Luddite]

You cannot determine the SIM lock from your account. It is determined by the phone messages. If you insert a locked SIM, you will see a message "Enter unlock (PUK) code". If you see no message and the phone is working, the SIM is not locked.

If you wish to lock the SIM, search your phone for that setting. But beware: if you do lock the SIM then enter the code incorrectly 3 times it will be permanently locked until your get a PUK code from the moderators.

[Korth]

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@Nonnowrote:

Thanks for the info.  Good to Know! . ..   but that doen't really answer my question.  In a "lost or stolen phone senario", I might not know that for a while . . .  in which case, the finder/thief can not only use the phone but get all the info off the SIM.  As per:  "A SIM card offers security for both the user's data and his or her calls. The cards can be locked, meaning that only someone who has the correct personal identification number (PIN) can use the card. If the phone is stolen, the thief cannot use a locked SIM or get any information off of it without the PIN"

Or is this a true statement?  I'm pretty much a newbie so I don't reall know (1)  if this is so and (2) how to determine (from my account info) if my SIM is locked.  That's what I really want to know . . .  how to determine this from my Account or Profile or ???  info on site.  Thanks again.  Hope I have made my question clearer.

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https://en.wikipedia.org/wiki/Subscriber_identity_module

Your phone is (or should be!) locked with a PIN or password which needs to be entered every time it's turned on.  It will only allow a limited number of failed attempts before it imposes delays on subsequent attempts or simply locks out the SIM card and/or the device itself.

The SIM card doesn't exactly contain account-specific information, it contains unique numbers (ICCID, IMSI, etc) which are associated with Public Mobile and lets them know which of their accounts is linked to it.  PM knows your Self-Serve account number, any personal information, and any credit cards you've submitted to them - but none of this stuff is encoded anywhere in the SIM card.

The SIM card does have a small NVRAM/Flash memory, and it might contain copies of stuff stored on your phone - personal information, account information, contacts, numbers, passwords, etc.  But this stuff is already on your phone, and most phone software never uses the (tiny and crowded) SIM for storage unless the user explicitly configures settings to do so for backup/migration purposes.  So chances are if you haven't deliberately stored this information on your SIM then it's not going to be stored there.

Most thieves would be far more interested in the phone than the SIM card.  If they turn it on and can get working service "free" (as in, somebody else paying) then they'll happily use it.  Otherwise they'll chuck the SIM card and try another one they know works, they'd be far more inclined to factory reset/erase the phone in the hopes of using the phone itself than to recover any information which might be stored on it.

SIM card readers can be purchased cheap on ebay and alibaba, they plug into a USB port and let anyone view or change the SIM card contents.  However most people have never even heard of these readers and all the good stuff stored on SIM cards is encrypted.

[Nonno]

Thanks for the info.  Good to Know! . ..   but that doen't really answer my question.  In a "lost or stolen phone senario", I might not know that for a while . . .  in which case, the finder/thief can not only use the phone but get all the info off the SIM.  As per:  "A SIM card offers security for both the user's data and his or her calls. The cards can be locked, meaning that only someone who has the correct personal identification number (PIN) can use the card. If the phone is stolen, the thief cannot use a locked SIM or get any information off of it without the PIN"

Or is this a true statement?  I'm pretty much a newbie so I don't reall know (1)  if this is so and (2) how to determine (from my account info) if my SIM is locked.  That's what I really want to know . . .  how to determine this from my Account or Profile or ???  info on site.  Thanks again.  Hope I have made my question clearer.

[SD08]

You can declare a phone/SIM lost by logging into your account here.
Go to:  Plan & Add-ons -> Lost/Stolen Phone -> Click on "Suspend Service"

If you find your phone, then you can go to the same place to reverse the process.