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Digital signature, Certificates – Nokia 6170 User Manual

Page 86

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Nokia 6170 User Guide

85

Copyright © 2004 Nokia

Mobile Internet services

Change module PIN—Change the module PIN, if allowed by the security module.

Change signing PIN—Select and change a signing PIN.

Digital signature

You can make digital signatures with your phone if your SIM card has a security
module. The signature can be traced back to you through the private key on the
security module and the user certificate that was used to perform the signature.
Using the digital signature can be the same as signing your name to a paper
bill, contract, or other document.

1

While browsing, select a link on a page, such as the title of the book you
want to buy and its price.

The text to sign (possibly including amount, date, etc.) is shown.

2

Check that the header text is Read and that the digital signature icon

is shown.

If the digital signature icon does not appear, there is a security breach. Do
not enter any personal data such as your signing PIN.

3

Scroll through and read all of the text before signing.

4

To sign the text, select Sign.

5

Select the user certificate you want to use, enter the signing PIN (provided
with the SIM card if the SIM card has a security module), and select OK.

The digital signature icon disappears, and the service may display a
confirmation of your purchase.

Cache memory

The information or services you access with the browser are temporarily saved in
the cache memory of the phone.

If you tried to access or have accessed confidential information requiring
passwords (for example, your bank account), clear the cache after each use.

To clear the cache from the menu, select Web > Clear the cache.

To clear the cache while browsing, select Options > Other options >
Clear the cache
.

Certificates

There are three kinds of certificates: server, authority, and user.

Certificates have a restricted lifetime. If Expired certificate or Certificate not
valid yet
is shown even though the certificate should be valid, check that the
current date and time settings in your phone are correct. Before changing these
settings, make sure that you really trust the owner of the certificate and that
the certificate really belongs to the listed owner.