Classifications

• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L63/00—Network architectures or network communication protocols for network security
  • H04L63/06—Network architectures or network communication protocols for network security for supporting key management in a packet data network
  • H04L63/062—Network architectures or network communication protocols for network security for supporting key management in a packet data network for key distribution, e.g. centrally by trusted party
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W12/00—Security arrangements; Authentication; Protecting privacy or anonymity
  • H04W12/04—Key management, e.g. using generic bootstrapping architecture [GBA]
  • H04W12/043—Key management, e.g. using generic bootstrapping architecture [GBA] using a trusted network node as an anchor
  • H04W12/0431—Key distribution or pre-distribution; Key agreement
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L63/00—Network architectures or network communication protocols for network security
  • H04L63/04—Network architectures or network communication protocols for network security for providing a confidential data exchange among entities communicating through data packet networks
  • H04L63/0428—Network architectures or network communication protocols for network security for providing a confidential data exchange among entities communicating through data packet networks wherein the data content is protected, e.g. by encrypting or encapsulating the payload
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W88/00—Devices specially adapted for wireless communication networks, e.g. terminals, base stations or access point devices
  • H04W88/02—Terminal devices

Definitions

• the invention relates to secure communication between a data processing device and a security module storing secret data.
• the invention applies to any type of data processing device performing computer tasks and requiring, during the execution of tasks, secret data stored on a security module with which it communicates.
• a data processing device may be for example a server, a mobile phone, a laptop or a fixed computer, a PDA (Personal Digital Assistant) type electronic assistant, a "LIVEBOX" type home gateway (LIVEBOX is a registered trademark of the applicant), a decoder for access to multimedia content, etc.
• the data processing device is a mobile telephone allowing access to a telecommunications network.
• the communication between the data processing device and the module can be arbitrary.
• This communication may be a wireless communication type GSM (Global System for mobile communications), Wi-Fi, bluetooth, Irda (Infrared Data Association), or other.
• This communication can also be wired type RTC (switched telephone network), ADSL (Asymmetric Digital Subscriber Line), or other.
• This communication may also consist of an electrical connection in the case of electrical coupling between the data processing device and the module, the module being a chip module provided with electrical contacts.
• This communication can also be a contactless link, the module being a contactless module (active or passive) equipped with data processing means and an antenna for communication with the Ie. device.
• this communication may also consist of a combination of all or part of the aforementioned types of communication.
• the invention applies to any security module able to store secret data and to communicate with a data processing device of the aforementioned type.
• This module is removable and can therefore, as such, communicate, as desired, with one of the aforementioned data processing devices.
• the module is a subscriber identity module USIM card type (Universal Subscriber Identity Module) coupled to a mobile phone.
• USIM module stores secret data such as encryption keys that the phone may require when performing a computer task.
• the invention is not limited to this type of card and can be extended to any type of module storing secret data whose transmission to a data processing device must be secured:
• a SIM card type module Subscriber Identity Module, GSM standard - TS 51.011
• a module of the UICC multi-application card type see TS 102.221 entitled "Smart cards; UICC-Telephone interface; Physical and logical characteristics" stores secret data and may therefore require secure communication with the device with which it is coupled.
• GSM, UMTS, and SCP standards in particular TS 102.223 for the PUICC administration commands for any technical questions relating to the operation of a module of SIM, USIM or UICC type, respectively.
• the module can also be a module for accessing a device of the encrypted multimedia content decoder type.
• a type of module stores the encryption keys to be transmitted to the decoder for the decryption of an encrypted content.
• a SIM card security module USIM or UICC.
• This module stores in its memory all the data relating, for example to a subscription, to a personal password, to the last numbers called, etc.
• certain data are secret and usable by the mobile phone for the execution of a computer task capable, for example, of reconstituting a scrambled content received from a content provider.
• a service may for example consist of viewing multimedia content directly on the screen of its mobile phone. These contents are paid and are thus scrambled voluntarily by the content provider.
• the scrambling may consist of an encryption of the multimedia content by means of an encryption key.
• the scrambling may also consist of the extraction of bits of information in the initial content, this extraction rendering the multimedia content unreadable.
• the encryption keys or the missing information bits then constitute secret data which can be delivered to the user, after payment to the content provider, and stored on his security module.
• the reconstitution of the content then consists, for the device, to require, with the module, the secret data stored in the module.
• the module transmits back the secret data requested.
• the device Upon receipt of the secret data, the device performs the computer task of reconstituting the initial content to be viewed by the user on his phone.
• This reconstitution can consist for example of a decryption by means of encryption key.
• This reconstitution can also consist in adding the bits of information extracted from the initial content.
• the big problem is that the connection between the phone and the security module is not secure.
• a malicious third party can then intercept the messages passing between the device and the module and extract the secret data.
• the knowledge of this data then gives the possibility to the malicious third party to fraudulently use the rights of a legitimate user for his own account without the content provider noticing it. More seriously, this third party has the opportunity to disseminate this secret data to other people. In the latter case, the number of frauds increases exponentially, thereby creating a certain revenue shortfall for a content
• An object of the invention is to secure a communication between a security module and a data processing device, particularly when this communication is for secret data to remain confidential, and this, whatever the device to which the module is connected .
• the subject of the invention is a method for creating a secure link between a data processing device and a security module, the data processing device being able to communicate with a security module that stores at least one security module.
• secret data k necessary for the execution by the device of a computer task, the data processing device and the security module being able to communicate with a telecommunications network, characterized in that it comprises the steps following:
• telecommunication delivers at least K encryption key to both the module and the data processing device identified
• a decryption step in which the device decrypts the result received by means of said at least one encryption key K received and obtains said at least one secret data item k,
• reception means able to receive at least one encryption key K
• encryption means capable of encrypting said at least one secret data k by means of said at least one encryption key K received
• transmission means for transmitting the result of the encryption of said at least one secret data item to the device executing its computer task.
• decryption means capable of decrypting the result received by means of said at least one encryption key K delivered, in order to obtain said at least one secret data item k,
• Execution means adapted to use said at least one secret data k for the execution of the computer task.
• the subject of the invention is also the trusted server, characterized in that it comprises:
• the invention also relates to a computer program adapted to be implemented on a trusted server, characterized in that said program comprises code instructions which, when the program is executed on the trusted server performs the steps following:
• the invention also relates to a computer program adapted to be implemented on a data processing device capable of communicating with a security module storing at least one secret data k necessary for the execution of a computer task. by the data processing device, characterized in that said program comprises code instructions which, when the program is executed on the data processing device performs the following steps:
• the encryption step having as its object the encryption of said at least secret data k by means of said at least one encryption key K,
• a trusted server transmits an encryption signal to both the module and the device in order to encrypt the transferring one or more secret data from the module to the device.
• This encryption of the communication guarantees the confidentiality of the secret data transmitted between the data processing device and the module.
• This solution also offers the advantage of securing communication between a module and a set of data processing devices with which the module can be made to communicate.
• the delivery of an encryption key may advantageously be performed at a convenient time. For example, when the module is removed from a data processing device and inserted into another device, the trusted server is able to deliver, preferably at insertion, a new key at a time to this other device. data processing and module to ensure the confidentiality of secret data transmitted between this other device and the module.
• Figure 1 is a block diagram of a computer system to which the invention can be applied.
• Figure 2 is an algorithm illustrating the various steps of an embodiment of the invention.
• FIG. 1 represents a SYS computer system in which the invention can be implemented. In this figure is shown
• a mobile phone MOB coupled to a USIM card type security module; in our example, the phone is UMTS type;
• a UT user of the mobile phone who is subscribed with a telecommunication operator to access r computer resources of a RES network by means of his mobile phone MOB.
• the MOB telephone comprises processing means such as a processor capable of executing computer programs for carrying out computer tasks consisting, in our example, of reconstituting scrambled content by means of a first encryption key k.
• processing means such as a processor capable of executing computer programs for carrying out computer tasks consisting, in our example, of reconstituting scrambled content by means of a first encryption key k.
• this scrambled content is encrypted content provided by an FDC content provider connected to the RES network.
• the MOB phone also includes memory means
• the USIM module includes processing means such as a processor capable of executing computer programs.
• the USIM module also comprises storage means, in particular for storing secret data necessary for reconstituting the scrambled content stored on the MOB telephone.
• the secret data is a first key to encryption k.
• the module USfM further comprises means for communicating with the telecommunication network RES.
• the USIM module is electrically cut off from the telephone.
• Another embodiment could have been consist of a communication between the USIM module and a server connected to the network, the server being capable of performing a computer task for which the execution requires the knowledge of secret data stored on the USIM module.
• the communication between the USIM module and the server is no longer direct, the phone, and possibly other data processing devices, can be intercalated between them.
• a trusted server SC is connected to the network RES.
• the purpose of this trusted server is to deliver a second encryption key K to both the phone and the USIM module.
• This second encryption key K has the function of encrypting the transmission of the first encryption key k from the USIM module to the MOB phone.
• only one second encryption key is transmitted.
• the invention is not limited to this example; the number of second encryption key K transmitted may be arbitrary.
• several second encryption keys can be used for the encryption of a first encryption key k.
• the trusted server can transmit several second encryption keys K en bloc in order to reduce the number of messages sent to the module and to the device;
• this trusted server SC preferably comprises means for authenticating the MOB telephone and the USIM module.
• the trusted server relies on any useful information at its disposal to perform the authentication.
• a first type of authentication possible is the verification of the validity of the certificate associated with the MOB phone
• This certificate is generally issued by a trusted entity called certification server ANU (also called public key architecture) known to those skilled in the art.
• This ANU certification authority server is able to guarantee that a certificate stored in a phone is a valid certificate and that it is not revoked.
• the trusted server SC can then refer to this certification server ANU to determine if the certificate is valid and thus authenticate the phone.
• a second type of authentication possible may consist of strong authentication. This second variant will be explained in the following description with reference to FIG.
• the authentication of the USIM module is based on an IMSI / ki pair intimately linked to a USIM module. This pair is stored in the USIM module and on an AUC authentication server.
• the authentication server performs a prior authentication step of the USIM module. This authentication verifies that the IMSI identity transmitted by the mobile is correct. This verification protects both the operator against the fraudulent use of its resources, and secondly the subscriber by prohibiting third parties to use his subscriber account.
• the trusted server SC can then refer to this USIM card AUT authentication server in order to authenticate the USIM module.
• the trusted server SC comprises means for communicating with the authentication server AUC of the security module.
• the trusted server communicates with the telephone-module pair through a GSM type mobile telecommunication network.
• This trusted server SC also comprises means for communicating with the telephone-module pair in order to deliver the second encryption die K. Preferably, this delivery takes place after a successful authentication of the phone and the module has taken place. This prior authentication step is not mandatory but necessary depending on the degree of security desired for transmitting the second encryption key K.
• the algorithm of FIG. 2 comprises various steps illustrating an exemplary implementation of the method of the invention.
• a USIM module is coupled to a telephone MOB.
• the mobile phone is powered on, and the USIM module is automatically authenticated by the AUT authentication server.
• This authentication step corresponds to that described above.
• the user UT activates a service for example by means of an interface present on his phone.
• the service consists of viewing multimedia content on a screen of the MOB phone.
• the provider downloads encrypted multimedia content to the MOB phone. This content is encrypted using the first encryption key k.
• tors of a third step ET3 the phone receives the encrypted content and stores it. This content can be decrypted either automatically without user intervention UT or on request of the user UT. _ _
• a signal is sent to the trusted server SC to inform it of the need to create a secure link between the MOB phone and the USIM module coupled to the phone.
• the origin of the signal can be varied. Its origin may be the MOB telephone, the USIM module, the content provider or any other element of the network having knowledge of the need for the phone to decrypt the encrypted content by means of a first encryption key k stored in the module.
• the signal is emitted by the USIM module.
• the USIM module has already been authenticated by the RES network when powering on the MOB phone, it remains for the trusted server to authenticate the MOB phone.
• the phone receives an encrypted content and sends a signal to the USIM module informing the need to secure the link between the MOB phone and the USIM module, the module in turn transmitting a signal to the trusted server SC for the inform of this need.
• the telephone could be the initiator of the signal.
• the phone would emit a signal directly to the module without signaling it to the trusted server SC to inform it of the need to secure the link between the MOB phone and the USIM module.
• the trusted server SC authenticates MOB phone identified by the authentication server ANU.
• MOB is for the trusted server SC to achieve strong authentication. This authentication takes place in several phases; During a first phase ET41, the trusted server SC tries to obtain from the MOB at least its public key KPU to verify with the certification server ANU that the certificate associated with this public key is valid.
• the trusted server SC transmits a challenge (also called random by the skilled person) to the mobile phone MOB.
• the mobile phone responds by signing this challenge using the private key stored in its certificate.
• the trusted server SC receives the signed challenge and verifies the veracity of this signature with the public key resulting from the certificate received during the ET41 phase.
• step ET6 If it turns out that the challenge has been signed by the right issuer with a valid certificate, the authentication is successful, and the process can be continued in step ET6. Otherwise, the authentication has failed, which means that the user can not use the service (see ET5).
• a fifth step ET5 if the authentication of the phone has failed, the trusted server SC does not continue the key issuing process.
• the user wishing to use the service returns to the first step ET1 or the second step ET2.
• the trusted server SC transmits, in a sixth step ET6, its second encryption key K to both the telephone and the USIM module.
• this second encryption key K is encrypted by means of the _ _
• This second encryption key K is also sent to the USIM module.
• the sending is done by SMS according to the standard 3GPP TS 03.48.
• the SMS is encrypted and its decryption can only be done by the USIM module.
• a seventh step E7 the USIM module transmits to the MOB phone the first encryption key k encrypted by means of the second encryption key K.
• the MOB phone receives the first encrypted key k by means of the second key K.
• a ninth step ET9 the telephone decrypts using the second encryption key K and obtains the first encryption key k.
• the phone then decrypts the encrypted content with the first encryption key k.
• the multimedia content can then be read by the user.
• the USlM module is removed from the MOB phone and inserted into another phone. The preceded resumes the same way in the first step ET2.
• key K is a session key. This key is then usable only temporarily, for example for the identified phone - ID -
• authentication of the module in step ET1 can take place at any time before the phone decides to transmit the second encryption key K.
• the fourth step ET4 can also take place before the third step ET3.
• the authentication of the phone takes place before the encrypted content is downloaded to the phone.
• the exemplary embodiment relates to a direct link between the data processing device and the module.
• the link is indirect, at least one other data processing device is intercalated between them.
• the task is performed by a data processing device that is not directly connected to the security module.
• the multimedia content is decrypted on any server of the network and that the phone is only used to view the decryption performed by this server.
• the trusted server transmits the second encryption key K to the server in question.
• step of issuing the second encryption key is preceded by a step of authenticating the data processing device and the module by the trusted server.
• This double authentication ensures that each actor, namely the data processing device that carries out the computer task and (e module that stores secret data is trustworthy before any encryption key transfer K.
• a single device requires a secure link with a single module.
• the number of authentication is, at best, equal to the number of device and module involved by a secure link.
• step 7 of our exemplary embodiment a single encryption key is transmitted to the phone and module that have been identified.
• this example is not limiting, in fact, for the same computer task to be performed by the device, for example the reading of a multimedia content, it is possible that several messages including secret data can pass from the module to the device. data processing.
• the trusted server in order to enhance the security, and if, preferably, the authentication of both the data processing device and the module is successful, the trusted server generates at least one session key as a key K encryption for performing the computer task.
• the trusted server SC transmits at least a second encryption key K, - o -
• the identification step is preceded by sending a signal to the trusted server (SC) to inform it of the need to create a secure link between the device and the module.
• the initiator of this signal may be any data processing device having knowledge of the need to encrypt the communication between the device and the module.

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• 2006
  • 2006-03-20 JP JP2008504813A patent/JP2008535427A/ja active Pending
  • 2006-03-20 US US11/918,190 patent/US20090044007A1/en not_active Abandoned
  • 2006-03-20 EP EP06726259A patent/EP1867189A1/de not_active Withdrawn
  • 2006-03-20 WO PCT/FR2006/050240 patent/WO2006106250A1/fr active Application Filing

Non-Patent Citations (1)

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