Certificate Management - Nokia N91 User Manual

Lock if SIM changed—You can set the device to ask for the
lock code when an unknown SIM card is inserted into your
device. The device maintains a list of SIM cards that are
recognized as the owner's cards.
Closed user group (network service)—You can specify a group
of people to whom you can call and who can call you.
When calls are limited to closed user groups, calls still may
be possible to the official emergency number programmed
into your device.
Confirm SIM services (network service)—You can set the
device to display confirmation messages when you are using
a SIM card service.
Glossary of PIN and lock codes
If you forget any of these codes, contact your service
provider.
Personal identification number (PIN) code—This code
protects your SIM card against unauthorized use. The PIN
code (4 to 8 digits) is usually supplied with the SIM card.
After three consecutive incorrect PIN code entries, the
PIN code is blocked, and you need to unblock it before
you can use the SIM card again. See the information
about the PUK code in this section.
UPIN code—This code may be supplied with the USIM card.
The USIM card is an enhanced version of the SIM card and
is supported by UMTS mobile phones. The UPIN code
protects the USIM card against unauthorized use.
PIN2 code—This code (4 to 8 digits) is supplied with some SIM
cards, and is required to access some functions in your device.
Lock code (also known as security code)—This code (5 digits)
can be used to lock the device to avoid unauthorized use.
The factory setting for the lock code is 12345. To avoid
unauthorized use of your device, change the lock code.
Keep the new code secret and in a safe place separate from
your device.
Personal unblocking key (PUK) code and PUK2 code—These
codes (8 digits) are required to change a blocked PIN code
or PIN2 code, respectively. If the codes are not supplied
with the SIM card, contact the operator whose SIM card
is in your device.
UPUK code—This code (8 digits) is required to change a
blocked UPIN code. If the code is not supplied with the
USIM card, contact the operator whose USIM card is in
your device.

Certificate management

Digital certificates do not guarantee safety; they are used
to verify the origin of software.
Glossary: Digital certificates are used to verify the
origin of the XHTML or WML pages and installed
software. However, they can only be trusted if the
origin of the certificate is known to be authentic.
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