Abstract:
A system for certifying documents transmitted digitally over a data communications network, such as financial transactions, registry office certificates and payments, comprising clients for accessing services provided by the various providers and a centralized system for assigning digital certificates and for verifying digital signatures applied by users of the system, each signing device being uniquely associated with a user independently of the service required, thus allowing the user to access a plurality of services by a single security instrument.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    The present invention relates to the field of services for identification and authentication on data communications networks, with particular reference to the field of digital signatures.  
           [0002]    During the last decade, data communications networks in general and the Internet in particular have gradually become widespread. This ongoing expansion is accompanied by the proliferation of new online serves, which over time gain the trust of consumers and become part of the daily activity pattern of the average user.  
           [0003]    Online services range from the possibility to access remote information resources, such as libraries, journalistic archives, historical archives, music archives and the like, to the possibility to make purchases and commercial transactions directly from home, to check one&#39;s bank accounts and perform stock-market transactions without moving from one&#39;s work station.  
           [0004]    Most public organizations, such as city councils, hospitals, registry offices, vehicle registration authorities, are increasingly orientated toward the use of data communications networks, with a consequent reduction of times and running costs.  
           [0005]    One of the biggest problems observed in using these services is the need to certify the identity of the parties that interact by means of the data communications network and the content of the documents transmitted between the customer of the service and the provider of the service.  
           [0006]    The type of services offered in fact requires the user to be identified assuredly before he can use the requested service.  
           [0007]    The most widely used identification method is the user&#39;s entry of a login, or user identifier, and of a password or secret code. The entry of this data pair is still used today in many cases to identify the user who is connecting to the server of the system operated by the service provider.  
           [0008]    The large number of services already available has recently called attention to a logistical problem that is strongly felt in the field: the need to remember an increasingly large number of identification data, typically logins and passwords.  
           [0009]    Moreover, this system, if used without further measures, is not even a sufficiently secure method, since often it is or can be bypassed by ill-intentioned experts in the field.  
           [0010]    The need for greater security, arising most of all from the fact that many services comprise commercial transactions (purchases, online trading, and so forth) has brought to the forefront new protection methods, such as digital signatures and certificates and smart cards with their readers, mechanisms for the authentication of electronic documents that have been introduced recently indeed to cope with the new requirements of the modern market.  
           [0011]    A digital signature can be seen as the online equivalent of the conventional signature on paper. By way of the statutory provisions that are in force in several states, including the Italian State, the digital signature is legally valid and has the same value as an autograph signature.  
           [0012]    The digital signature process is based on an infrastructure known as PKI (Public Key Infrastructure) and on known asymmetric cryptography techniques. Every party that has a digital signature certificate is given a pair of keys: a “public” key, which can be freely queried and distributed to the public, and a “private” key, which must remain secret and is stored in a signing device, which is usually a smart cart protected by an access PIN (Personal Identification Code).  
           [0013]    The digital signature is used for two different purposes: ensuring the integrity of a message and authenticating the identity of the sender.  
           [0014]    The sender, using his private key, signs the message so that the signature can be verified by anyone by using the sender&#39;s public key, after verifying the validity of the public key at a Certification Authority. This verification occurs by means of the digital certificate, which is a signed electronic document issued by the Certification Authority. The digital certificate is usually attached to each electronic message sent by the sender to the recipient, and is used mainly to establish the relationship between a name and a public key, so as to ensure the identity of the signer and give the recipient the means to encrypt a reply.  
           [0015]    Although on the one hand, from the point of view of service providers, the level of security can be considered to have improved considerably with respect to what was available a few years ago, the same cannot be said for the user or customer side, which has to interact with increasingly varied and complex infrastructures, a plurality of signing devices and cards to be kept in one&#39;s pocket or wallet, each of which can be activated by means of a different PIN or password, with consequent difficulty in memorization and awkwardness in use.  
           [0016]    The situation in this regard can only worsen in the future, with the introduction of electronic identity cards, smart cards of the Chamber of Commerce, ATM cards, credit cards, club cards, and so forth.  
           [0017]    Each one of these cards, in order to allow access to the corresponding online service, must ask the user for its individual identifier and be accompanied by its individual signing device, such as a reader and a keypad for entering a code, which is interposed between the network client, i.e., the station from which the service is requested, and the corresponding server of the provider, in order to request and obtain authorization for the service.  
           [0018]    This is only an example of interposition of the signing device between the request of a service and the service itself. The same occurs, in different manners, depending on the type of station used by the user to request the service. For example, if the Internet is used, in some cases a screen is displayed within the user&#39;s browser, and the user can enter his login and password, which vary for each service, in the screen; in other cases, the digital certificates installed in the browser itself are used automatically. As an alternative, proxy applications are used which filter all the requests and intercept the ones that must be signed, furthermore forcing the user to work necessarily from his own station.  
           [0019]    The current background art proposes, as a solution to the above mentioned problem, the centralization of the data required to access the services on a single card, for example a programmable Java card, which ensures isolation of the application inside it. Such a solution, however, has been found to be unsatisfactory for several reasons. In particular, the production costs are borne by the organization that dispenses the first service to which the user subscribes: the organization must bear the costs for the physical production of the card, which is then also used by other organizations for various services; moreover, the memory of the card is limited and therefore can support a finite number of services; finally, the need remains to physically interpose a different signature instrument between the client and the server depending on the service that is required.  
         SUMMARY OF THE INVENTION  
         [0020]    The aim of the present invention is to overcome the problems noted above, by providing a new method and system for authenticating users on request that does not require the interposition and use of a different signing device for each service requested by the user.  
           [0021]    Within this aim, an object of the present invention is to centralize the identification and authentication system and unify or minimize the signature instrument, customizing it on the user and not on the service requested by the user.  
           [0022]    Another object of the present invention is to relieve the user from the burden of memorizing a large number of keywords or secret codes, which cannot be kept in writing or electronically for security reasons.  
           [0023]    This aim and these and other objects that will become better apparent hereinafter are achieved by a system for authenticating users on data communications networks, preferably but not exclusively on the Internet, comprising a plurality of signing devices and a plurality of client stations  30  from which access is gained to a plurality of servers  20  operated by a plurality of service providers, characterized in that each one of the signing devices is associated with a user and is suitable to generate a digital signature on behalf of the associated user, independently of the client station used.  
           [0024]    This system comprises the following steps: sending to a server of a service provider, from a client station, a request to a service, the request comprising at least one identifying data item of a user; searching for the URI (Uniform Resource Identifier) of a signing device associated with the user; sending a signature request to the signing device; by means of the signing device, signing the request and sending it to the server. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0025]    Further characteristics and advantages of the invention will become better apparent from the following detailed description that follows, given by way of non-limitative example and accompanied by the associated figures, wherein:  
         [0026]    [0026]FIG. 1 is a schematic view of the system according to the invention;  
         [0027]    [0027]FIG. 2 is a flowchart for the request of signature and authentication data;  
         [0028]    [0028]FIG. 3 is a flowchart according to the inventive method on which the present invention is based;  
         [0029]    [0029]FIGS. 4, 5,  6 ,  7  and  8  exemplify a possible implementation of messages exchanged among the parties involved in the described system for implementing the inventive concept on which the present invention is based. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0030]    [0030]FIG. 1 illustrates a preferred embodiment of the architecture of the system according to the invention. In particular, FIG. 1 illustrates a centralized server  10 , operated by an identification service provider, hereinafter designated as the “certifier”, which is connected to a database  15  and to a data communications network  5 ; a server  20  of a generic service provider, which is connected to a database  25  and to the data communications network  5 ; two client stations  30  and a signing device  40 , which are also connected to the data communications network  5 , and a user  80 .  
         [0031]    The elements shown schematically in FIG. 1 are illustrated by way of example and illustrate what is actually a plurality of client stations, a plurality of signing devices, a plurality of servers and corresponding archives operated by service providers and/or by the certification authority.  
         [0032]    The operation of the system is divided into two separate steps: a first step for the registration of the user  80  at the centralized identification system  10 , and a second step for actual use.  
         [0033]    The first step, shown schematically in FIG. 2, is performed only once when the user  80  needs to subscribe to any service that participates in the system according to the present invention.  
         [0034]    The user  80  goes to an authorized service provider  20  and gives his identification data in order to obtain access to the service offered by the provider  20 .  
         [0035]    The service provider  20  physically recognizes the identity of the user  80  (step  200 ) and sends to the certifier  10  significant data related to the user (step  205 ). Upon receiving a new registration ( 210 ), the centralized server  10  sends ( 215 ) a message  41  to the signing device  40 , enabling it for the request of a certificate. The signing device  40  receives ( 220 ) the authorization and sends ( 225 ) the certificate request, for example according to the PKCS10 standard, in a message  42 . If it is not able to generate key pairs autonomously, at the same time it requests the server to issue the certificate, for example according to the PKCS12 standard format, which also comprises the private key.  
         [0036]    The certifier  10  enters the new user  80  in its database  15 , assigning to the user a unique identifier and generating for the user a digital certificate and, if necessary, also the pair of signing keys (step  230 ). Once the certificate has been generated, the certifier sends ( 235 ) a message  43  to the signing device  40 , enabling it for collection.  
         [0037]    The signing device can be any instrument, provided that it can be connected to the data communications network  5 , directly or indirectly by way of suitable gateways that are already known in the field.  
         [0038]    The device can therefore be a personal computer, preferably a portable one, a GPRS or UMTS cellular telephone, a handheld, or any other wireless or wired device, in which suitable management software is or can be loaded, said software being used to handle the messages in the cited formats and to apply the digital signature of the user  80  by using his private key.  
         [0039]    This device is assigned a URI (Uniform Resource Identifier), which allows to identify the location of the signature instrument of the user  80  within the data communications network  5 .  
         [0040]    The URI is preferably stored both in the database  15  of the certifier  10  and in the database of the service provider  20 . However, it is possible to provide for storage at only one of the two parties without thereby altering the inventive concept that is the basis of the invention, as will become better apparent hereinafter.  
         [0041]    From this moment onward, if the user  80  wishes to access another service managed by a participating provider  20 ′, he merely has to ask the provider  20 ′ for an identifier that is local to the system of the provider  20 ′ and allows to identify him among the various users.  
         [0042]    The provider  20 ′ then stores, within its database, the identifier as assigned by it to the user  80 , as well as the URI of the signing device chosen by the user  80  to apply his digital signature.  
         [0043]    With reference to the flowchart of FIG. 3, the operation of the system in the second step, i.e., when the user  80  wishes to access a service provided by a provider  20  contracted with the centralized system  10  and with which the user  80  is registered, is as follows.  
         [0044]    The user  80  connects from a client station  30  to the server of the service provider  20 , sending in a conventional manner a request to access the service. Merely by way of illustration, it is now assumed that the client station  30  has an Internet browser and that the service provider  20  is a bank that offers a home banking system.  
         [0045]    The user  80  is connected, by means of his browser, to a site for accessing the service provided by the provider  20  and enters, for example in a field of the HTML page of the site or in a window that appears when requested by the server, his identification code for the requested service, for example his taxpayer identification code (step  300 ).  
         [0046]    The server  20  of the service provider verifies ( 305 ) the received identifier, searching for it ( 306 ) in its database  25 . If it is not found, the server  20  sends an error message to the browser, asking to enter a valid identifier.  
         [0047]    If the user  80  is instead correctly registered in the database  25 , the server  20  retrieves ( 310 ) the information related to the URI of the signing device  40  of the user  80 , and asks the device to sign the request to access the service submitted by the browser (step  315 ) by means of a message  44  sent with a standard protocol, for example HTTP, or a proprietary protocol.  
         [0048]    The device, upon receiving the message  44 , displays to the user  80  the terms of the request. The user  80  then enters the code that enables the use of his private key to sign the access request (step  320 ), by keying it in on his own signing device  40 , for example his mobile phone, his handheld or an application that runs on the computer itself. The result  45  thus obtained is returned to the server  20  as a response to the request.  
         [0049]    The server  20  receives the digitally signed request and verifies it locally or by sending it ( 325 ) in turn to the server  10  of the certifier.  
         [0050]    In this last case, the certifier verifies the signature, by using the public key of the user  80 , which is transmitted together with the request or is found in the database  15 . The mechanism is preferably based, as currently occurs, on calculating the hash, this term being used to designate a known algorithm that calculates a “fingerprint” of the transmitted text, said hash being then compared ( 330 ) with the hash calculated and encrypted when the user  80  sent the request.  
         [0051]    If the comparison between the calculated hash and the transmitted hash produces identical results, the centralized identification server  10  returns a positive response to the server  20  of the provider of the home banking service. Otherwise, the returned response corresponds to an error indication.  
         [0052]    The server  20  of the service provider checks the received response ( 335 ) and evaluates its outcome ( 336 ). If it is positive, it enables ( 340 ) the access to the client  30  of the user  80 , who at this point can perform the requested operation ( 345 ), since it is certified that this operation is correctly authorized.  
         [0053]    Clearly, the user  80  is not constrained to using a single client station. On the contrary, the inventive concept on which the present invention is based finds its maximum expression in the possibility of the user  80  to use an unlimited number of services, without altering the possibility to have a single digital signature instrument.  
         [0054]    For example, the user  80  can now go to the automatic counter  30 ″ of the city council to request a family status certificate. The server  20 ″ of the registry office requests on-screen the entry of an identification data item, for example the taxpayer identification code, checks whether it exists in its database  25 ″, retrieves the URI of the corresponding signing device  40 , and sends to the signing device  40  the request to sign the service access request.  
         [0055]    Once again, the user  80  must enter on his signing device the code for activating the hash calculation algorithm and for sending the digitally signed request to the server  20 ″.  
         [0056]    As in the previously described case, the server  20 ″ sends the received data to the server  10  of the centralized identification system and satisfies the requests of the user  80  if the outcome of the checking operations is satisfactory.  
         [0057]    [0057]FIGS. 4, 5,  6 ,  7  and  8  illustrate an exemplifying and non-limitative implementation, in the XML language, of the messages  41 ,  42 ,  43 ,  44  and  45  respectively, which illustrates in practice the flow of information among the parties involved in the system.  
         [0058]    It has thus been shown that the present method and system achieve the intended aim and objects. In particular, it has been shown that the signing device thus conceived allows to centralize the operations for verifying the identity of users and for authenticating transmitted documents independently of the service that is requested, with a considerable saving of resources. Moreover, the system thus conceived, by allowing the uncoupling between the client station and the signing device, allows to use data communications technology in manners that currently can be used only through conventional methods. For example, a securities investment company or a financial broker can operate on behalf of a user, buying or selling shares from their work station, while the authorization signature is input simultaneously by the user himself, wherever he may be. Likewise, it is possible to perform secretarial work, which then requires the signature of the person responsible, without requiring the physical presence of the user at the station where the secretarial staff works, since the authorization to proceed is obtained only after the entry of the digital signature on the part of the signing device controlled by the user  80 .  
         [0059]    The many problems of delegating to work on behalf of third parties, for example in requesting certificates or in collecting postal material, are thus solved, since the validity of the signature applied by the user is independent of who is physically acting on his behalf.  
         [0060]    Clearly, numerous modifications are evident and can be promptly applied by the person skilled in the art without abandoning the scope of the protection of the present invention. For example, it is obvious for the person skilled in the art to acquire the information related to the URI of a signing device in any location accessible by way of the data communications network  5 , for example by using a centralized system for URI resolution, and it is likewise evident that communication among the described parties can also occur by using a plurality of data communications networks, for example by using portions of private networks in some of the described steps.  
         [0061]    It is also evident that the inventive concept on which the present invention is based is independent of the physical location and of the manner in which the user identification data are processed; said location and manner can be different from the cited mechanism for pairing user identifier/URI of the signing device.  
         [0062]    Therefore, the scope of the protection of the claims must not be limited by the illustrations or by the preferred embodiments shown in the description as examples, but rather the claims must comprise all the characteristics of patentable novelty that reside in the present invention, including all the characteristics that would be treated as equivalent by the person skilled in the art.  
         [0063]    The disclosures in Italian Patent Application No. M02002A000006 from which this application claims priority are incorporated herein by reference.