DE102010054783A1 - Method for storing elementary file of card in subscriber identity module for e.g. smart phone, involves storing file content in volatile memory area of carrier for use during operating data carrier when file includes determined attribute - Google Patents

Abstract

The method involves receiving (17) a file content i.e. updated file content, of a file in a portable data carrier during operating the data carrier. An attribute i.e. high update activity attribute, of the file with the received file content is checked (18) by the data carrier. The file content is stored (19) in a volatile memory area i.e. RAM, of the data carrier for use during operating the data carrier when the file includes the determined attribute. The file with an original file content is stored in a non-volatile memory area i.e. ROM, of the data carrier. Independent claims are also included for the following: (1) a computer program product comprising instructions for performing a method for storing a file in a portable data carrier (2) a portable data carrier comprising an integrated semiconductor circuit.

Description

The invention relates to a method for storing a file in a portable data carrier, a computer product and a portable data carrier.

In a portable data carrier is preferably to disk with appropriate security features such. Smart cards, smart cards, tokens, mass storage cards, multimedia cards and / or electronic identity documents, such as an electronic identity card, a passport with machine-readable identification data of a person stored on a chip. For example, a chip card is understood by the term portable data carrier, wherein the field of application of the chip card is very diverse, for example as credit or debit payment card, health card, access authorization card, company ID card, identification card, electronic vehicle registration or driving license. In particular, a subscriber identification card, SIM card for short, for the purpose of identifying a subscriber in a mobile radio network is understood by the term portable data carrier. on.

Alternatively, the data carrier can also be a security element integrated in a mobile terminal. The security element is configured in particular as a hardware component and arranged as a fixed integrated component in the mobile terminal, where it can not be removed either in the form of the mobile device, for example as M2M module, co-processor or as a trusted processor part, such as Trusted Base. Alternatively, the security element can be connected as a removable module with security functionality with the mobile terminal in, for example in the form of a smart card, in particular a Subscriber Identification Module, short SIM card, mass storage card, USB token, mass storage card, Secure MicroSD card, as Mobilfunknetztoken , z. B. a UMTS surf stick. Alternatively, the security element is designed as a software component in the form of a trusted platform module as a trusted part of the operating system kernel of the mobile terminal or as a security software algorithm.

The file system of a volume comprises according to the 5th edition of the "Handbuch der Chipkarten" by the authors Wolfgang Rankl and Wolfgang Effing, hereafter referred to as Rankl / Effing, published 2008 by the Carl Hanser Verlag, page 502 ff at point 13.7 "File Management" Directory files such as the Master File, MF for short, or Dedicated Files (DF) and individual files, referred to as Elementary Files, short EF.

According to Rankl / Effing, the file system is stored in a rewritable non-volatile memory area, for example the EEPROM or FLASH memory of the portable data carrier, so that the file system is also available after disabling the data carrier. The management and organization of the files in the file system is taken over by the operating system of the data medium.

In an object-oriented structure of the file system, the files have a file descriptor, also referred to as a file header, in which all information about the file itself is contained. Furthermore, the files have the file content, also referred to as a file body, in that the user data of the file is contained. The file descriptor again contains the attribute of the file, which identifies special properties of the file. The file descriptor may be fixed or variable in length.

Parts of the file system of today's portable data carrier can be updated for maintenance purposes, innovations, enhancements and / or error correction subsequently, that is to say after the data carrier has been issued to a user. A part of the file system includes, for example, an application with a directory file DF and associated files EF. A part of the file system is, for example, an application for obtaining any functionality. The changes or updates of the file system affect the file contents of a single or multiple files in the file system or only certain parts of a file content of a file are replaced by current parts of the file content.

In today's data carriers, the number of read / write accesses in nonvolatile memory is limited and highly dependent on the technology in which the nonvolatile memory has been fabricated, the manufacturing process itself and the environment in which the semiconductor chip is operated. This number decreases with increasing efficiency and simultaneous area reduction of the storage areas in the data carrier. A semiconductor chip manufacturer usually guarantees a minimum number of write cycles. Typically, a manufacturer of an EEPROM will guarantee memory between 100,000 and 500,000 write cycles, and a FLASH memory will guarantee up to 100,000 write cycles. If the guaranteed minimum number of write cycles to a sector / block or to the same byte in a memory area is reached, the functionality of the chip is not guaranteed. In most cases, the data carrier is no longer functional and must be replaced.

The problem is exacerbated when the disk is used as a firmly integrated component in a End device is introduced, for example, a machine-to-machine, short M2M modules or a trusted processor area. On the one hand such data carriers should have longer operating times, on the other hand, the data carrier can not be replaced in a simple manner. Most of the time the entire terminal has to be replaced.

In order to avoid such problems, for example, a wear leveling method is used for the operation of nonvolatile memory areas. By this method, an unused or previously unused non-volatile memory area sector is used to write the updated file content instead of immediately re-describing a sector with updated data contents after an erase operation. Thus, the number of read / write accesses can be effectively increased.

Alternatively, the disk manufacturers often give the hint describing the non-volatile memory by means of software routines, such as program code loops, complex register evaluations, etc., to circumvent, so that the non-volatile memory area must be described less frequently in order to achieve the highest possible lifetimes of the disk. It is disadvantageous that a programmer of software for the disk in the design of its software code must restrict, in particular the performance of the disk by higher computational effort, program runtime and can be massively weakened by such bypass software routines.

The invention is therefore based on the object to significantly increase the lifetime of portable data carriers and in particular to significantly reduce write accesses to a non-volatile memory area. The goal is to prevent costly workarounds, so that a programmer can use all the possibilities and benefits of the data carrier. The process should be easy to implement and efficient.

The object of the invention is achieved by the measures described in the independent independent claims. Advantageous embodiments are described in the respective dependent claims.

The object is achieved in particular by a method for storing a file in a portable data carrier. The file has a file descriptor and a file content. In a first method step, a file content of the file is received during the operation of the data carrier. In a second method step, an attribute of the file is checked by the data carrier whose file content has been received. The file content is stored in a volatile memory area for use during this operation of the volume if the file has a particular attribute.

Storage in the volatile storage area is understood in particular to mean that the file contents are not transported further into the non-volatile storage area and stored there. Until the end of the session, the file content is stored exclusively in the volatile memory area. If this file content is necessarily needed during the session, it is not loaded from the nonvolatile memory, as usual, but is loaded directly from the volatile memory area, for example the random access memory RAM.

Creating new files is also included in this procedure. If, for example, the CREATE FILE command is received in the data carrier and the file has the specific attribute, the file is generated exclusively in the volatile memory area and discarded after the session has ended.

An attribute of the file of a portable data carrier is in particular Rankl / Effing under item 12.9 "Attributes of Files" from page 474 described. They are used to mark special properties of the file. The attribute is recorded in the file descriptor. This file descriptor has a pointer to the original file content of the file in an object-oriented structure. File descriptor and original file contents are stored in a nonvolatile storage area of the volume. A particular attribute in the sense of logon is an attribute that indicates a particular property of the file or file content. This property of the file indicates to the method according to the invention that the file content can be discarded after the end of the session of the data carrier and thus in particular is stored only in the volatile memory area of the data carrier.

The term operation of the data carrier is synonymous with the term session or session of the data carrier. In this case, the data carrier has been made operable by means of a terminal, wherein it is supplied in particular by a power supply and possibly further supplying electrical signals, such as reset, clock etc. from the terminal. If the data medium is operable in a session and receives file contents, these are preferably only available in this session. If the supply signals are deactivated by the data carrier, the operation of the data carrier ends, the session is thus terminated.

In particular, the file content is an updated file content and the file is already stored with an original file content in a nonvolatile storage area of the volume. A disk-aware update command is the UPDATE BINARY / RECORD, which updates an original file content on a disk.

In the context of the application, the term "updated file content" is understood to mean the replacement of an original file content already stored in the non-volatile memory area. Alternatively, the term is also understood to mean that a reloadable file content is received in addition to already existing file content, which may also be discarded when the session of the volume is terminated. The term updated file content thus also includes reloadable file content.

In contrast to the prior art, in which any update of file contents is stored as a backup in the nonvolatile memory, in the method according to the invention, an attribute is first checked and, depending on the attribute, it is determined whether storage in the nonvolatile memory area is necessary. This saves a lot of time, which would be needed to access the non-volatile memory. Since volatile memory, such as RAM cells, can be written much more frequently, the life of the medium is drastically increased.

Advantageously, the updated file content is stored exclusively in the volatile memory area, so that the updated file content is discarded unsecured upon deactivation of the data carrier. Therefore, if it is determined by the attribute that an update of the file content is not necessary, the updated file content is not stored in the non-volatile memory area.

The invention makes use of the fact that a multiplicity of updates of file contents need not be stored permanently and is only necessary for one session of the data carrier. Therefore, these updates are stored only in the volatile memory area.

When the data carrier is restarted, ie at the beginning of a new session, the original file content of the file is loaded from the non-volatile memory area.

In particular, the data carrier is a subscriber identification module for a mobile radio network. A construction and operation of such data carriers is detailed in the specification ETSI 3GPP TS 11.11 / 51.011 or the ETSI 3GPP TS 31.102 described. In this GSM / USIM specification, the files are also defined, which in turn may be updated. The file is thus in particular an elementary file of a SIM card file system.

Advantageously, the particular attribute is the "High Update Activity" attribute. This attribute identifies files that are updated very frequently, which can dramatically decrease the life of the media when using these files frequently. Therefore, media manufacturers always warn against it and advise a programmer not to use such files at all, although use during a disk session is quite advantageous. The problem is that these files are always overwritten in the same sector of the non-volatile memory, so that special memory cells are loaded excessively often, whereby a drastic reduction in the operability of the disk is achieved. The method according to the invention makes it possible to use files with this attribute without disadvantages since it can be assumed that updating the files has no relevance after the session has ended and can be discarded.

In a preferred embodiment, the name of the file is checked in addition to the attribute. If file contents are updated to remove corrupted file contents or to present information to a user, it is useful not to discard this update unsecured. An enumeration of the respective file names can be taken from the description of the figures.

In a further advantageous embodiment, an update counter is incremented in the data carrier if the updated file content is stored only in the volatile memory area of the data carrier. The count of the update counter is stored in the non-volatile memory area so that it is available even after the session has ended. The counter reading is stored, for example, in the file descriptor of the file whose updated file content was received and is also requested when the attribute is checked. Alternatively, with each updated file content, the version of the file is also transmitted so that access to the non-volatile memory area can be completely prevented.

Advantageously, the count of the update counter is compared with a predefined value. In this case, the updated file content is stored in the non-volatile memory area, regardless of the attribute of the file, if the counter reading exceeds the preset value. A default value is x-arbitrary. For example, can be achieved in this way advantageous In this way, every xth update can be stored in the non-volatile memory area, so that the other nine updates that have since been received are discarded.

It is particularly advantageous if the updated file content, irrespective of the attribute, is always first stored in the non-volatile memory area when the original file content is first updated. Most updates in the field are only meaningful the first time, so this first update of the original file content is also useful in the non-volatile storage space. All subsequent updates are discarded because they are only relevant to the current session.

In particular, the updated file content is received by means of over-the-air service from a remote mobile station in a mobile network in the data carrier. In this application, a mobile radio network is understood as a technical infrastructure on which the transmission of signals for mobile radio takes place. In this case, the mobile switching network, in which the transmission and switching of the signals take place between stationary devices and platforms of the mobile radio network, as well as the access network (also referred to as air interface), in which the transmission of the signals between a mobile radio antenna and a mobile terminal takes place, to understand. For example, the "Global System for Mobile Communications", short GSM as a representative of the so-called second generation or the General Packet Radio Service, GPRS short and Universal Mobile Telecommunications System, short UMTS as a representative of the so-called third generation of mobile networks are mentioned here by way of example the third generation, the mobile switching network is extended by the ability of a packet-oriented data transmission, but the radio network is in itself unchanged.

Alternatively, the updated file content is received through a communication link with a terminal in the volume. This is done either via a contact interface or a contactless interface. The operating system of the data carrier is designed so that the update of the file content via the contactless interface of the data carrier, for example, according to one of ISO / IEC 14443 . 15693 . 18092 or contact according to ISO / IEC 7816 or USB standard is received.

The inventive concept further comprises a computer program product which is loaded directly into the volatile or non-volatile memory of the data carrier and comprises software code sections with which the preceding embodiments of the method according to the invention are executed when the product runs on the data carrier.

The inventive concept further comprises a portable data carrier with a semiconductor integrated circuit. The circuit includes a communication interface for receiving an updated file content of a file, a volatile storage area for storing the updated file content, and a nonvolatile storage area for storing an original file content and a file descriptor of the file. The volume further includes a verification unit that stores an attribute of the file and the updated file content only in the volatile memory area for use during operation of the volume if the file has a particular attribute.

Preferably, the solid state integrated circuit of the data carrier further comprises an update counter, wherein the update counter is incremented when the updated file content ( 12a ) and a comparison unit, wherein the comparison unit compares the count of the update counter with a preset value. The original file content in the nonvolatile memory area is thereby overwritten by the updated file content if the comparison of the comparison unit shows that the counter reading is equal to or greater than the preset value.

In the idea of the invention, any type of attributes or markings of the files as a criterion for being a specific attribute are conceivable in order to use the method according to the invention.

The invention or further embodiments and advantages of the invention will be explained in more detail with reference to figures, the figures only describe embodiments of the invention. Identical components in the figures are given the same reference numerals. The figures are not to be considered as true to scale, it can be exaggerated large or exaggerated simplified individual elements of the figures.

Show it:

1 Receiving an updated file content over a cellular network according to the prior art

2 A block diagram of functional units of a introduced in the portable data carrier semiconductor circuit according to the prior art

3 A file system with files in a SIM card according to the prior art

4 An object-oriented structure of a file consisting of file descriptor and file content according to the prior art

5 A flow chart of a first embodiment of a method according to the invention for storing a file in a data carrier

6 An alternative embodiment of the invention in 5 shown flow chart

7 An alternative embodiment of the invention in 5 and 6 shown flow chart

1 shows a system consisting of a mobile terminal 5 with an internal terminal circuit 5a , In the mobile terminal 5 is still a portable data carrier 1 in the form of a SIM card. The disk 1 But could also be designed according to one of the manner described above and in the terminal 5 be integrated. The terminal 5 is in 1 a mobile station and by means of a cellular connection 6 with a remote mobile device 7 in a communication connection. Part of the mobile device 7 is an update server 7a , On the SIM card 1 is an unplayed file system whose files 10 a file content 12 have, via the update server 7a can be updated. The update of the file system 8th and the files it contains 10 in the SIM 1 is done by an update command 15 , initiated by the remote mobile station 7 by means of OTA. Alternatively, this can be used to operate the SIM 1 necessary terminal 5 make the pending update.

This in 1 shown terminal 5 is for example a smart phone, a PDA or an alternative mobile device 5 , It is primarily suitable for a mobile connection 6 with a mobile radio instance 7 , About a non-illustrated mobile antenna receives the terminal 5 the updated file content 12a as part of the file system 8th on the SIM 1 , This update is done by the terminal 5 to the SIM 1 transfer. In the SIM 1 becomes the original file content 12b through the updated file content 12a in the non-volatile memory area 4b replaced. The update takes place at irregular intervals and for a variety of purposes, in particular for remote maintenance, error correction, information message and the same more.

In 2 is an exemplary block diagram of one in the disk 1 introduced semiconductor circuit 2 shown. The semiconductor circuit comprises a central processing unit CPU, at least one interface I / O, via which a contact-based and / or contactless communication connection to the terminal 5 is possible. This I / O interface becomes the volume 1 made operational by the necessary signals, in particular the power supply, the clock, the reset signal and possibly other data channels are transmitted. The transmission takes place for example via an electrical line or an electromagnetic field.

The semiconductor circuit 2 also has a volatile memory area 3 on, in particular a random access memory, short RAM. This memory is characterized by fast access times compared to other storage technologies and the loss of memory content when power is lost. Furthermore, in the circuit 2 a nonvolatile memory area 4 intended. This storage area 4 has a rewritable nonvolatile memory 4a and a rewritable nonvolatile memory 4b on. The memory 4a is, for example, a read-only memory that is described during a production and / or personalization phase with files that are unchangeable in scope 4a are stored. The memory 4b however, is repeatedly writable. Priority is given to the memory area 4b designed for today's data carriers in EEPROM or FLASH technology.

The in 2 illustrated data carrier 1 now receives the in. via the I / O interface 1 mentioned updated file content 12a in the form of APDU and transmits this updated file content 12b to the arithmetic unit CPU. The CPU, in turn, has some access rights to the volatile memory area 3 as well as the non-volatile memory areas 4a and 4b , According to the prior art and the GSM and ETSI specifications mentioned in the introduction, after reception of the updated file contents 12a causes the updated file content 12a into the non-volatile rewritable memory area 4b is stored.

In 3 is an exemplary file system 8th represented according to the prior art. The file system has a master file, MF and two dedicated files DF1, DF2 as directory files 9 on. Hierarchically subordinate, each DF has two elementary files EF1, EF2 and EF3, EF4, hereafter referred to as files 10 be designated. In 3 A directory file DF1 may include a further directory file DF3, which in turn contains elementary files EF5, EF6. Will now while under an update command 15 updated file contents 12a for the files EF1, EF2 received, then the original file contents 12b through the updated file contents 12a As part of the Update 15 replaced, so to speak, the file contents 12b with the file contents 12a overwritten. Because of this file content 12 always on the same sector of the rewritable memory area 4b This sector may be described more often than other sectors that are only read, eventually reaching the maximum write access number. Thus, these sectors diminish the memory area 4b the lifetime of the disk 1 and in particular lead to its inoperability. Especially for permanently inserted data carriers 1 in the terminal 5 This can lead to massive costs, as an exchange of the data carrier 1 is expensive.

In 4 now becomes an object-oriented structure of a file 10 shown. There is a file descriptor 11 shown. The descriptor 11 , also referred to as a file header, contains the administratively relevant information of the actual file content 12 , The file descriptor 11 has an attribute on it 13 on which the property of the file 10 features. As an attribute 13 In particular, there is the WORM attribute, which indicates that the corresponding file 10 written only once, but may be read multiple times. Another attribute 13 is the EDC attribute, a label that indicates the file contents 12 this file 10 is particularly sensitive and equipped with an Error Detection Code, EDC for short, in order to detect the tipping over of individual memory bits in the non-volatile memory immediately. As an attribute 13 is also the atomic write access provided, a label that this file 10 may only be written completely or not at all. Other attributes can be assigned for interface management, disk booting, file encryption, and more.

A very important attribute for this application 13 is the attribute for frequent writing, English: High Update Activity. This is a label for a file 10 which is updated very frequently and accordingly many read / write accesses to the nonvolatile memory area 4b caused.

The actual file content 12 the file 10 is again contained in the file body. The file critic 11 always has a pointer to the address of the memory area 4b in which the file contents 12 to the descriptor 11 belongs, is stored. When updating file content 12 does not have to be a complete sentence of the original file content 12b with the updated file content 12a In particular, only parts of the file content can be made 12b to be updated. Thus, an update command 15 an updated file content 12a for only a fraction of an original file content 12b include.

In the context of the application, the term "updated file content" is understood to mean the replacement of an original file content already stored in the non-volatile memory area, but also rechargeable file content.

In 5 is a program flow of a method according to the invention shown. This is the disk 1 put into operation, which is shown with a session start. With commissioning is the supply of the data carrier 1 with clock, reset, voltage and possibly other signals to understand. During the session the reception takes place 17 an updated file content 12a , Receiving is here in 1 Suggestively explained and not explicitly part of the invention. Is the reception 17 completed according to the invention, the check 18 on the attribute 13 the file 10 containing the updated file content 12a concerns. This attribute 13 is either during the reception 17 received with or alternatively by reading the to the updated file contents 12a belonging file descriptor 11 in the non-volatile memory area 4b he follows. The following is called a specific attribute 13 the attribute "High Update Activity" is used, the invention is not limited thereto.

Will in the review 18 the attribute 13 "High Update Activity" does not recognize the updated file contents 12a in the non-volatile memory area 4b written. In particular, the associated original file content 12b overwritten.

Will, however, during the review 18 the attribute 13 "High Update Activity" detected, so the updated file content is only in the volatile memory area 3 , in particular the RAM memory stored for this session. The file content 12a can be used for this session and stands for all necessary operations in the volume 1 ready. In the specification ETSI TS 102 241 become card-internal processes for SIM / USIM cards 1 For example, the "FILE UPDATE EVENT" process that will continue to work if the updated file content 12a exclusively in the volatile memory area 3 is stored. The updated file content 12a namely for applications, such as Java Card Applets, on the disk 1 still completely transparent and will continue to be usable without problems. This means in particular that an application is still triggered when for a file 10 the application an updated file content 12a has been received and it does not matter if the updated file content 12a in the volatile memory 3 or in nonvolatile memory 4b is stored.

If the volume is disabled, for example, by ending the session, the RAM loses space 3 its content and the updated file content 12a is discarded. When the disk is re-commissioned, the original file content is restored as needed 12b from the non-volatile memory area 4b loaded.

With saving in RAM 3 It is understood that the files no longer in the non-volatile memory area 4b are stored and until the end of the session exclusively in RAM 3 are stored.

According to the mentioned specification, all files should be 10 in the non-volatile memory area 4b be filed. By applying the method according to the invention are specially marked files 10 just not updated, because these files 10 no meter readings or other continuous file contents 12 show the interaction between the mobile network 6 , Terminal 5 and disk 1 would affect. In the present case, the updating of the files is radically dispensed with since this update is important only for this current session and is otherwise irrelevant. To the RAM 3 should not unnecessarily overload attributes 13 of files 10 be chosen because of the limited size of the RAM 3 not too big, in particular a few bytes.

According to 6 is an alternative embodiment to that in 5 shown process flow diagram shown. The process histories differ only in that after checking 18 of the specific attribute 13 another check 20 of the file descriptor 11 , in particular the name of the file to be updated 10 he follows. If this check 20 that results in updating the file 10 in the non-volatile memory area 4b must be made, regardless of the attribute 13 so will this update of the file contents 12 in the non-volatile memory 4b written.

If this check 20 that results in updating the file 10 not in the non-volatile memory area 4b so this will be the update of the file contents 12 only in volatile memory 3 saved.

• – EF Loci
• – EF Kc
• – EF KcGPRS
• – EF LociGPRS

The following are examples of EF file names 10 listed the attribute 13 Have "High Update Activity" and easily after completing the session of the disk 1 can be discarded:

• - EF Loci
• - EF Kc
• - EF KcGPRS
• - EF LociGPRS

This listing is not complete. As already mentioned, other attributes or other markings may be used to apply the method of the invention.

As an alternative to the "High Update Activity" attribute, files can also be used 10 be used for the inventive method, which contain an identification that they at a booting of the terminal 5 not from the disk 1 read and during an update process in the volume 1 be received.

In 7 is one to the 5 and 6 illustrated alternative embodiment. In contrast to 5 will be after receipt 17 incrementing 21 one, in the volume 1 provided update counter, take place. Subsequently, a comparison is made 22 of the count of this update counter with a preset value X. If the count is equal to or greater than the value X is independent of the attribute check 18 or further review 20 saving the updated file content 12a in the non-volatile memory area 4b ,

With this configuration, it is possible every x-th update of a file 10 store.

Alternatively, this update counter may be incremented if it is determined that the updated file content 12a only in RAM 3 is stored.

Alternatively and not shown, an update count is received at the time when the updated file content 12a Will be received. Based on the supplied meter reading, the comparison 22 performed and decided whether the file contents in the volatile memory area 3 or in the non-volatile memory area 4 is stored.

It is also conceivable that the file descriptor 11 a label about the file version 16 and with the reception 17 the current version is communicated. Based on the version 16 the file 10 a decision is made as to whether the file content is in the volatile memory area 3 or in the non-volatile memory area 4 is stored.

In particular, and not shown here further, the update takes place in the non-volatile memory area 4b in any case, when the first update of the file 10 was received, as these are for the correct operation of the disk 1 , the terminal 5 and the remote mobile station 7 be necessary.

In a further embodiment, not shown in the figures, the received updated file content 12a in the non-volatile memory area 4b saved when the file contents 12a from the original file content 12b strongly different. Using the example of the EF loci as an example of this strong distinction, if another MCC (Mobile Country Code) or another Mobile Network Code (MNC) is in the Location Area Identity (LAI) field of the updated EF loci instead of the original EF loci ,

LIST OF REFERENCE NUMBERS

1

Portable data carriers; SIM

2

Integrated circuit

3

Volatile storage area, RAM

4

Non-volatile memory area

4a

Non-volatile write-once memory ROM

4b

Non-volatile rewriteable memory, EEPROM, FLASH

5

terminal

5a

Internal terminal circuit

6

Mobile connection, OTA

7

Mobile instance,

7a

update server

8th

file system

9

Directory Master File (MF), Dedicated File (DF)

10

File, Elementary File (EF)

11

File descriptor

12

file content

12a

Updated file content

12b

Original file content

13

Attribute of the file

14

Part of the file content

15

update command

16

file version

17

Updating an EF received

18

Check the attribute of the EF

19

Store the EF depending on the attribute of the EF

20

Save the EF depending on the EF

21

Increment the update counter

22

Compare the update count with preset value

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited non-patent literature

• 5th edition of the "Handbook of Chip Cards" by the authors Wolfgang Rankl and Wolfgang Effing, hereinafter referred to as Rankl / Effing, published in 2008 by the Carl Hanser Verlag, page 502 ff at point 13.7 "File Management" [0004]
• Rankl / Effing under item 12.9 "Attributes of Files" from page 474 [0017]
• ETSI 3GPP TS 11.11 / 51.011 [0025]
• ETSI 3GPP TS 31.102 [0025]
• ISO / IEC 14443 [0032]
• 15693 [0032]
• 18092 [0032]
• ISO / IEC 7816 [0032]
• ETSI TS 102 241 [0058]

Claims (14)

Procedure for saving a file ( 10 ) in a portable data carrier ( 1 ), where the file ( 10 ) a file descriptor ( 11 ) and a file content ( 12 ) comprising the steps of: receiving ( 17 ) of a file content ( 12 ) of the file ( 10 ) during operation of the data carrier ( 1 ) in the data carrier ( 1 ); and - checking ( 18 ) of an attribute ( 13 ) of the file ( 10 ) whose file contents ( 12 ) was received by the data carrier ( 1 ); characterized in that the file content ( 12 ) in a volatile memory area ( 3 ) of the data carrier ( 1 ) for use during this operation of the data carrier ( 1 ) is saved when the file ( 10 ) a certain attribute ( 13 ) having. The method of claim 1, wherein the file content ( 12 ) an updated file content ( 12a ) and the file ( 10 ) with an original file content ( 12b ) in a nonvolatile memory area ( 4b ) of the data carrier ( 1 ) is stored. The method of claim 2, wherein the updated file content ( 12a ) exclusively in the volatile memory area ( 3 ) of the data carrier ( 1 ), so that the updated file content ( 12a ) when deactivating the data carrier ( 1 ) is discarded unsecured. Method according to claim 2 or 3, wherein upon restarting the data carrier ( 1 ) the original file content ( 12b ) of the file ( 10 ) from the nonvolatile memory area ( 4b ) of the data carrier ( 1 ) is loaded. Method according to one of the preceding claims, wherein the data carrier ( 1 ) a subscriber identification module for a mobile radio network ( 6 ). Method according to one of the preceding claims, wherein the file ( 10 ) an elementary file of a file system ( 8th ) of a SIM card and the particular attribute ( 13 ) is the "High Update Activity" attribute. Method according to one of claims 5 or 6, wherein when checking ( 18 ) of the attribute ( 13 ) also the name of the file ( 1 ) is checked. Method according to one of the preceding claims, wherein in the data carrier ( 1 ) an update counter is provided which upon receipt ( 17 ) of the file content ( 12 ) is incremented ( 21 ), if the updated file content ( 12a ) only in the volatile memory area ( 3 ) of the data carrier ( 1 ) is stored. The method of claim 8, wherein the count of the update counter is compared to a preset value, and wherein the updated file content ( 12a ) regardless of the attribute ( 13 ) of the file ( 10 ) in the nonvolatile memory area ( 4b ) is stored when the count exceeds the preset value, whereby the original file content ( 12b ) from the updated file content ( 12a ) is overwritten. Method according to one of the preceding claims, wherein the updated file content ( 12a ) regardless of the attribute ( 13 ) in the nonvolatile memory area ( 4b ) is saved when the original file contents ( 12b ) is updated for the first time. Method according to one of the preceding claims, wherein the updated file content ( 12a ) by means of over-the-air service ( 6 ) from a remote mobile station ( 7 ) or by a communication link with a terminal ( 5 ) in the volume ( 1 ) Will be received. Computer program product which is loaded directly into the volatile or non-volatile memory of the data carrier and comprises software code sections, with which the method steps according to one of the preceding method claims 1 to 11 are executed, when the product runs on the data medium. Portable data carrier ( 1 ) comprising a semiconductor integrated circuit ( 2 ) with: - a communication interface (I / O) for receiving ( 17 ) of an updated file content ( 12a ) of a file ( 10 ); - a volatile memory area ( 3 ) to save ( 19 ) of the updated file content ( 12a ); and - a nonvolatile memory area ( 4b ) to save ( 19 ) of an original file content ( 12b ) and a file descriptor ( 11 ) of the file ( 10 ); characterized in that the data carrier further comprises a verification unit which has an attribute ( 13 ) of the file and the updated file content ( 12a ) only in the volatile memory area ( 3 ) for use during operation of the data carrier ( 1 ) is saved when the file ( 10 ) a certain attribute ( 13 ) having. Portable data carrier ( 1 ) according to claim 13, wherein the semiconductor integrated circuit ( 2 ) of the data carrier ( 1 ) further comprises: an update counter, wherein the update counter increments ( 21 ), if the updated file content ( 12a ) is received; A comparison unit, wherein the comparison unit compares the count of the update counter with a preset value; characterized in that the original file content ( 12b ) in the nonvolatile memory area ( 4b ) from the updated file content ( 12a ) is overwritten when the comparison of the comparison unit reveals that the count is equal to or greater than the preset value.

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