Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
106 words
A method of accessing data in a file system of a data
processing system which includes a programmable central
processor unit, and an operating system, the data of the
file system having a digital signature identifying the data,
characterised by the steps of performing a checking
algorithm to calculate (19) an authentic signature for the
data, reading the identifying signature from the file
system, comparing (20) the authentic digital signature of
the data with the digital signature read from the file
system, and accessing the file data in response to a match
between the authentic digital signature and the digital
signature read from the file system.
Claim 2
Dependent Claim
23 words
A method as claimed in claim 1, wherein the data
comprises a directory of file entries having a digital
signature identifying the directory.
Claim 3
Dependent Claim
35 words
A method as claimed in claim 1, wherein the data
comprises one or more file entries within a directory of
file entries, one or more of the file entries having an
associated identifying digital signature.
Claim 4
Dependent Claim
17 words
A method as claimed in claim 3, wherein the directory has
a digital signature identifying the directory.
Claim 5
Dependent Claim
60 words
A method as claimed in claim 3 or 4, wherein the file
entries are each associated with an attribute indicating
that the file entry is protected by an encrypted digital
signature and are each associated with a key, the method
comprising reading (20) the signature for a file entry and
decrypting (27) the signature by means of the associated
key.
Claim 6
Dependent Claim
89 words
A data processing system comprising a programmable
central processing unit, an operating system (10), and a
file system for data which has a digital signature to
identify the data, the file system being provided with a
file system driver (12) including means to perform a
checking algorithm to generate an authentic digital
signature, means to read the identifying digital signature
from the file system and means to allow access to the data
only in response to a match between the authentic signature
of the data and the identifying signature.
Claim 7
Dependent Claim
34 words
A system as claimed in claim 6, wherein the file system
is adapted to store the data in the form of a directory of
file entries which has a digital signature identifying the
directory.
Claim 8
Dependent Claim
41 words
A system as claimed in claim 6, wherein the file system
is adapted to store the data in the form of file entries in
a directory of file entries, one or more of the file entries
having an associated digital signature.
Claim 9
Dependent Claim
24 words
A system as claimed in claim 8, wherein the file system
is adapted to store a digital signature identifying the
directory of file entries.
Claim 10
Dependent Claim
60 words
A system as claimed in claim 8 or 9, wherein the file
system is adapted to store each of the file entries in
association with an attribute to indicate whether the file
entry is protected by an encrypted digital signature and in
association with a key, the file system having means to
decrypt each encrypted key using the associated key.