Abstract:
A method, software and apparatus facilitates one or more third-party agents to securely access a customer&#39;s or other first party&#39;s private personal and financial data or other such confidential information from a second party, preferably on the Internet. A security document or ticket is presented to the second party for verifying the customer&#39;s consent to grant such access to the third party. The second party only communicates such confidential information to the third party if the security document is found to be valid. The security document, which can be at least partially encrypted, can also include a preselected expiration time, beyond which it is not valid.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is entitled to the benefit of, and claims priority to, U.S. Provisional Patent Application Ser. No. 60/223,825, filed Aug. 8, 2000 entitled “INTERNET THIRD-PARTY AUTHENTICATION USING ELECTRONIC TICKETS.” 
    
    
     BACKGROUND AND SUMMARY OF THE INVENTION 
     The invention relates generally to computer information security and the Internet, and more specifically to methods that permit one or more third-party agents to access customers&#39; private personal and financial data or other confidential information on the world-wide-web. The invention was originally designed as a method for banks and bank customers to mutually approve one or more third party agents (such as aggregators, for example) to access customer confidential data via the Internet. It is also applicable, however, in any situation involving computers where an agent&#39;s computer or computers act as an intermediary between computers of two other parties and where access to certain information is to be limited, whether or not the information is confidential. 
     The Consumer Problem 
     When the World Wide Web (“the web”) was invented in 1990, security was not a major concern because it was primarily used to share scientific research. The initial concept was for unlimited, open, public access to documents. As the web became popular, however, the need for security increased. Web sites developed schemes with usernames and passwords to protect confidential web pages. And, in 1995, SSL encryption became the standard method to protect confidential data transmitted over the public Internet. By 1999, consumers started to become confident in the security of Internet transactions, and Internet commerce became commonplace. Millions of consumers regularly made purchases, paid bills and performed common banking and brokerage transactions using the Internet. 
     Today, a typical consumer might have access to dozens of secure web sites for shopping and financial services. Because each site has a unique look and feel, customers must learn how to navigate each individual site. Each site also has a unique security identification and authentication scheme, forcing each customer to keep track of dozens of usernames and passwords, PINs and code words. These factors may be confusing and frustrating for consumers. So, while the Internet revolutionized the way consumers access information, taking advantage of it is often difficult and cumbersome. Obtaining a consolidated view of a customer&#39;s Internet or on-line accounts could easily require hours of manual effort, working at a computer, visiting many web sites. 
     The Aggregator Solution 
     An aggregator is a web service that consolidates a consumer&#39;s financial and personal information and presents it in a concise, easy-to-read fashion. An aggregator accesses shopping and financial service web sites to extract customers&#39; data and repackages that data for presentation on the aggregator&#39;s web site. After enrolling with an aggregator, customers only need to learn how to navigate the aggregator&#39;s web site. Furthermore, customers must remember only one username/password combination, instead of dozens. 
     The enrollment process typically involves setting up a username and password to access the aggregator&#39;s web site. This username/password becomes a very powerful “master password” because it gets linked to the customer&#39;s other accounts and passwords. In addition to creating master passwords, customers also enter details about each bank, brokerage and shopping web site they want the aggregator to access on their behalf. Details include usernames, passwords, account numbers and other secret or confidential information required to access aggregated web sites. (Not all aggregators know how to access all financial and shopping web sites, so the aggregator must support the bank, brokerage and shopping web sites a customer intends to use.) Once the aggregator has the information necessary to access all of a customer&#39;s accounts, however, the aggregator will work behind the scenes on the Internet to assemble the details about the customer&#39;s personal financial life or other confidential information. 
     When a customer visits the aggregator&#39;s web site, the aggregator will typically display a list of bank, credit card, brokerage, shopping and other financial accounts, along with associated balances, in a concise, consistent and consolidated fashion. The aggregator&#39;s site usually also has features to “drill down” into details about any account, showing transactions, history and trends. If the aggregator offers bill payment features, customers can also view on-line versions of bills and statements, including transaction details. Many aggregators also allow customers to schedule bill payments—where the aggregator moves money from customers&#39; bank accounts to vendors or other accounts either electronically or by mailing actual checks. Since an aggregator may track uncleared transactions, the financial information kept by an aggregator may be more up to date than customer&#39;s account data at each bank, brokerage or vendor. An aggregator makes customers&#39; on-line financial life much easier to manage. The aggregator is, in effect, a personal financial agent on the Internet. 
     How Do Aggregators Work? 
     Many aggregators use a technique known as “screen scraping” to access customers&#39; information at various financial and shopping web sites. During screen scraping, the aggregator simulates a human and Internet browser accessing each web site. A computer program takes the place of a keyboard and mouse by supplying the expected input. Much like a human reading results on a screen, the computer program “reads” and stores the information returned by each aggregated site. 
     Screen scraping is not a perfect technology, however. If a web site changes its appearance or process flow, the aggregator may not be able to accurately obtain (or scrape) the information from the web site. Aggregators must constantly monitor aggregated web sites in an attempt to keep their computer programs current with each site. 
     In contrast, some aggregators have tightly coupled relationships with various financial institutions. This enables them to use more advanced techniques such as Interactive Financial Exchange (IFX), Open Financial Exchange (OFX) or eXtended Markup Language (XML), for example, to efficiently transfer account information. However, these techniques have not yet been widely adopted. 
     Risks of Aggregation 
     Many consumers recognize the benefits provided by aggregators, but feel uncomfortable providing aggregators unlimited access to passwords and other private information. If the security at an aggregator&#39;s web site is compromised, unscrupulous parties could steal customers&#39; private and confidential information and passwords. 
     When banks and other commercial web sites created their username/password schemes, they intended that only the consumer associated with each username know the secret password. In many cases, banks don&#39;t even store actual passwords. Instead, they store only a mathematically hashed value based on the password, which is enough information necessary to detect a valid password. In other words, many banks don&#39;t actually know a password, but they can determine if the customer really knows it. Storing password information in this manner reduces the likelihood of password theft by bank employees. This method also helps prevent password theft by Internet hackers. 
     When consumers provide passwords to an aggregator, they reduce the security and safety of their passwords because they are stored at an aggregator&#39;s computing facility in a reproducible form. Even if the aggregator stores encrypted passwords, this is less secure than a mathematical hash, because, unlike a bank, the aggregator can reproduce the original passwords. An aggregator&#39;s unscrupulous employee or an Internet hacker could exploit this risk and steal passwords. 
     Banks, brokerages and retail companies, for example, created their web sites with the intent that actual customers would access their sites. They didn&#39;t intend for aggregators&#39; automated systems to extract customer data. The web sites&#39; auditing and record logging mechanisms were originally intended to track actual customers initiating transactions. Commercial web sites need a way to audit and record accesses by aggregators distinctly from actual customers. These audit mechanisms should have a way to determine if a customer actually approved each aggregator&#39;s access. 
     If a customer discontinues the use of an aggregator, he or she would request the aggregator to disable their username and clear their personal information. However, this does not guarantee that the customer&#39;s confidential information has been removed. For a variety of legitimate reasons, or in the event of error, the aggregator might retain records of the customer&#39;s associated accounts, usernames and passwords. This retention might be temporary, but could even be permanent. The customer has no method to detect when an aggregator accesses his accounts, so they cannot easily feel confident that all access has been terminated. 
     The risks described here, plus financial liability and other regulatory risks, are roadblocks to widespread acceptance of aggregators by consumers, commercial web sites and government regulators. 
     Public Key Cryptography and Digital Certificates 
     Much of public key cryptography relies on unique properties of extremely large prime numbers (hundreds or more digits long) and a technique patented in 1983 by R. L. Rivest, A. Shamir, and L. M. Adleman. This technique, commonly known as RSA encryption (named for its inventors), allows any general-purpose computer to generate a pair of mathematically related numbers, known as encryption keys (or just “keys”), within a few seconds. Typically, one of the keys is called the private or secret key because the key owner must protect and secretly store the only copy of the private or secret key. The other number is called the public key because it can safely be shared with anyone. 
     Although the RSA methods can easily generate a key pair within a few seconds, the process to reconstruct a key pair is extremely difficult. If one key in a pair is lost, it could take the world&#39;s fastest computers many years to decompose the known key and recalculate the lost key. This disparity in decryption is the strength of public key cryptography. If someone has your public key, it is very difficult (almost impossible) for him or her to determine your private or secret key. If you have someone&#39;s public encryption key, you can use RSA&#39;s encryption techniques to encode a message or file that only that person can decrypt and read. The message recipient must have the private key (which is associated with the public key) and use RSA&#39;s decryption techniques to decode the message. 
     Conversely, if someone uses his or her private or secret key to encrypt some data or its digest, then anyone with access to that person&#39;s public key can decrypt the data or its digest back to its original form. Assuming that the originator protects his private or secret key, nobody else could have sent the original encrypted message—in effect a mathematical signature proves who originated the message. (Within the computer security industry, this exemplary security device is commonly known as a digital signature.) 
     The public and private or secret keys complement each other. If one of the keys encrypts (or locks) some data, the other complementary key decrypts (or unlocks) the data. Each customer, commercial web site and aggregator must have a unique public and private key pair. Rather than inventing methods to manage the storage of private keys and sharing of public keys, this invention relies on the existing public key infrastructure (PKI). With PKI, when an entity (person or company) creates a key pair, they register the public key with a certifying authority (CA). The CA verifies the identity of the entity and issues a digital certificate, which has been digitally signed by the CA. 
     The digital certificate serves as a tamper-resistant electronic identification document for an entity. The digital certificate includes the entity&#39;s public key. (Only the entity that generated the key pair should have access to the associated private or secret key.) Much of the software required to manipulate and store digital certificates and associated keys already exists as commercially available software. Most Internet web browsers and web servers have the capability to store digital certificates and keys, and software libraries, such a RSA&#39;s CryptoJ can perform public key cryptography. It is expected that this invention will be implemented using tools such as these, among others. 
     Although the technology exists, and the software is readily available, the use of digital certificates has not yet been widely adopted by consumers. By the year 2000, the United States federal government and many states approved the use of digital certificates and digital signatures as acceptable authentication mechanisms for public-to-government transactions. As public and commercial acceptance of digital signatures become commonplace, it is expected that most commercial institutions will either issue or otherwise assist customers to obtain digital certificates. 
     SSL Encryption 
     The Secure Sockets Layer (SSL) protocol was developed by Netscape Communications, Inc. as a way to securely move data over a public network, notably and typically over the Internet. SSL uses public key cryptography, specifically RSA&#39;s encryption methods, for example, to establish a secure “session” between two computers connected via the TCP/IP protocol. Public keys, usually obtained from digital certificates and associated private or secret keys may be used to identify (authenticate) one or both computers in a TCP/IP conversation. Once an SSL session is established, it is very difficult (almost impossible) for a third party to eavesdrop and examine the data flowing between the end computers. This invention assumes that SSL encryption, or similar encryption protocols among those readily known by those skilled in the art, will be typically used for all secure communications between customers, aggregators and commercial web sites. 
     Optionally, SSL authentication may also be used to verify the identity of one or both parties involved in each communication. If both parties use public keys from digital certificates, for example, and associated private keys in conjunction with SSL to authenticate their identities with each other this is commonly referred to as SSL mutual authentication. If only one party uses a private or secret key and digital certificate for one end of an SSL session, this is commonly referred to as SSL single-end authentication. 
     Although this invention works best with SSL mutual authentication, it may also be used with SSL single-end authentication or even if SSL authentication is not used at all. In these cases, the parties must select some other form of verification or authentication (e.g., usernames and passwords), which should occur immediately after each SSL session is established. This invention requires that the parties involved in electronic communications, for example, have somehow verified or authenticated their identities with each other, using SSL authentication, for example, or similar techniques well-known to those skilled in the art. 
     Other known encryption/decryption methods will also occur to those skilled in the art, including those using symmetric, asymmetric, message digests (mathematical hashes), or other encryption schemes (including those using multiple-use or one-time use keys), for example. 
     Using the present invention, a tamper-resistant security document, such as an electronic document, known as a ticket, is created and approved by two consenting parties to allow a third party (or even more parties) to access private and confidential personal and financial data on the Internet (world-wide-web). The electronic ticket or other types of security documents can also have a limited lifetime, allowing the consenting parties to control the third party&#39;s duration of access. 
     Some of the exemplary features, objects or advantages of the present invention include:
         (a) to provide an electronic document (ticket), for example, that proves that two or more parties consent to allow a third party (or more parties) secure verified access to confidential information;   (b) to create an electronic document (ticket), for example, that is very difficult (almost impossible) to forge;   (c) to create an electronic document (ticket), for example, that is very difficult (almost impossible) to modify without the creator&#39;s consent;   (d) to create an electronic document (ticket), for example, that is only useful to the intended parties—a stolen ticket can&#39;t be successfully used by a thief,   (e) to create an electronic document (ticket), for example, that eliminates, or least substantially minimizes, damaging security consequences if it is lost or stolen;   (f) to create an electronic document (ticket), for example, that only needs to be stored by a single party;   (g) to create an electronic document (ticket), for example, with a limited lifetime—the ticket can&#39;t be used after it expires;   (h) to create an electronic document (ticket), for example, whose expiration date and time (“expiration time”) is agreed upon by all parties;   (i) to create an electronic document (ticket), for example, that can be used by a third party an unlimited number of times (or alternately, if desired in particular situations, for a specified limited number of times) during the ticket&#39;s lifetime;   (j) to create an electronic document (ticket), for example, containing a serial number allowing the ticket&#39;s approval and usage to be monitored and recorded for auditing purposes;   (k) to create an electronic document (ticket), for example, that allows the consenting parties to insert optional information into the ticket for subsequent, future usage; and/or   (l) to create an electronic document (ticket), for example, that may be safely substituted in situations where a traditional password would normally be used.       

     Possible further objects and advantages are to provide an electronic document (ticket) that can be initiated by any of the three or more parties, that allows customers, for example, to use third party agents to access confidential financial and personal information in a safe and secure and verifiable manner without requiring customers to reveal confidential passwords, and that also utilizes existing Internet technologies. Other objects, advantages and features of the invention will readily occur to those skilled in the art from the following description and appended claims, taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS. 1A and 1B  are flow diagrams showing an exemplary relationship of the entities involved in exchange of confidential information in relation to the invention. 
         FIGS. 2A through 2F  are flow diagrams showing an exemplary sequence of events performed in the context of the invention. 
         FIG. 3  is an exemplary illustration of what a customer sees on a computer screen during the approval of an electronic ticket or other such security document according to the invention. 
         FIG. 4  is a flow diagram showing an exemplary simplified flow of a ticket&#39;s request, approval and usage between three parties (in the illustrated example): an aggregator (the requestor), a commerce web site (the originator and first approver), and a customer (the final approver). 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     For purposes of illustration,  FIGS. 1 through 4  (taken in conjunction with the following description) illustrate merely exemplary embodiments of the invention, shown in the context of a commonly-encountered customer, aggregator and bank relationship for securely communicating a customer&#39;s personal and private banking, commerce-related information or other confidential information over the Internet. One skilled in the art will readily recognize that the present invention is equally applicable to other contexts in which confidential information is securely communicated among three or more parties, and even those using communication media other than the Internet. 
     As illustrated in  FIG. 1A , commerce web sites  103 ,  104  provide customers  101  access to customer private or confidential data  105  using the Internet  102 , standard operating software  107 ,  112  and computers  103 ,  110 . Although  FIG. 1A  only shows one instance of customer private data  105 , it is not uncommon for a customer  101  to have data scattered at many commerce web sites  103 ,  104 . 
     As illustrated in  FIG. 1B , an aggregator&#39;s web site  116  uses the Internet  102  and standard Internet software  121  to access many commerce web sites  103 ,  104  on behalf of the customer  101 . An aggregator  116  will access a customer&#39;s private data  105  from various commerce web sites  103 ,  104  and consolidate (with database software  121 ) the customer&#39;s private data  117  for later access by the customer  101 . When a customer  101  accesses the aggregator&#39;s web site  116 , his consolidated private information  117  is presented in a concise, easy-to-use fashion. A customer  101  need only access the aggregator&#39;s web site  116  to view their consolidated private or confidential information  117  originally obtained from many commerce web sites  103 ,  104 . 
     Most commerce web sites  103 ,  104  and a customer&#39;s general operating software (such as an Internet browser)  112  use SSL encrypted sessions  108 ,  109  to protect confidential data as it traverses the public Internet  102 . SSL uses public key cryptography, in conjunction with private keys  106 ,  111  and public keys (contained in digital certificates  114 ,  115 ) to authenticate the identity of one or both parties involved in each SSL session  108 ,  109 . 
     Commerce web sites  103 ,  104  create a public/private key pair suitable for use with RSA encryption and SSL software  107 ,  112 , for example. A commerce web site  103  also registers its public key with a certificate authority  113 , who will issue a digital certificate  114  containing the public key of the commerce web site  103 . Techniques for registering, sharing and processing digital certificates are well-known and are already widely available with standard Internet operating software  107 ,  112 , and are thus not described here. The invention assumes that digital certificates  114 ,  115 ,  127 , for example, and/or the public keys necessary for SSL and RSA encryption, are easily available to all parties that need access to them. 
     Digital certificates  114 ,  115 ,  127  and private or secret keys  106 ,  111 ,  118 , for example, may be used to authenticate the identity of both parties involved in any SSL session  108 ,  109 ,  122 ,  123 ,  124  using SSL mutual authentication. Alternatively, SSL single-end authentication may be used to create an SSL session  108 ,  109 ,  122 ,  123 ,  124  if only one party possesses the necessary private key and digital certificate. Although this invention works best with SSL mutual authentication in most situations, it may also be used with SSL single-end authentication or even if SSL authentication is not used at all, provided that an alternate means to authenticate the non-SSL authenticated party is utilized. Alternate authentication means are beyond the scope of this exemplary illustration of the invention, however they typically involve some sort of password scheme. 
     As illustrated in  FIG. 1B , this exemplary embodiment of the invention includes software  120 ,  125 ,  126  to create and process security documents or tickets  119 . Although this invention was designed to use the Internet  102 , more specifically, the world-wide-web technology of the Internet, it is also suitable for use when all or part of the information flows over private networks or other systems or mediums. 
     Software  120  at an aggregator&#39;s web site  116  sends a ticket  119  to each commerce web site  103 ,  104  for each access to a customer&#39;s private data  105 . Ticketing software  125  at a commerce web site knows how to validate a ticket  119  presented by software  120  from an aggregator&#39;s web site  116 . Once a ticket  119  is validated, the aggregator  116  is permitted access to the customer&#39;s private data  105  for the duration of the session  122 . If, however, an aggregator&#39;s web site  116  doesn&#39;t have a valid ticket  119  for the specific customer  101  and commerce web site  103 ,  104 , the aggregator&#39;s ticketing software  120  will send a ticket request to the commerce web site&#39;s ticketing software  125 . 
     Ticketing software  125  at the commerce web site  103  creates the first part of a new ticket and digitally signs it with the commerce site&#39;s private key  106 . All or part of the new ticket is then encrypted with the customer&#39;s public key  115  and sent back to the aggregator&#39;s web site  116 . If the customer  101  is not already on line with the aggregator&#39;s web site, when he or she next visits the aggregator&#39;s web site  116 , ticketing software  120  then forwards the encrypted, new ticket to ticketing software  126  contained in the customer&#39;s computer  110 . 
     Ticketing software  126  in the customer&#39;s computer  110  decrypts the new ticket, validates the commerce site&#39;s digital signature against the proper digital certificate  114 , and prompts the customer  101  to accept or reject the new ticket. The customer  101  can also be given a chance to adjust the ticket&#39;s expiration date and time. Based upon the customer&#39;s  101  response, the ticketing software  126  completes the ticket (including the customer&#39;s accept or reject status) and digitally signs the ticket with the customer&#39;s private key  111 . 
     The customer&#39;s ticketing software  126  and Internet browser  112  then forwards the completed ticket from the customer&#39;s computer  110  back to the aggregator&#39;s web site  116 . The aggregator ticketing software  120  then stores the ticket  119  for later use. 
     In  FIG. 2A , a typical procedure for granting and using an exemplary ticket is described generally, but not exclusively, as set forth below. 
     Consumers need a way to approve aggregators&#39; access to their various accounts without giving away their passwords. The ideal method should allow access to be easily revoked and audited. The invention contemplates the use of temporary, electronic tickets to fulfill these needs. 
     Tickets leverage existing Internet technology and public key cryptography to create tamper-resistant documents (tickets) which are used to approve account access. Tickets can be created by banks, brokerage firms, shopping sites and other commerce web sites, approved by customers, and given to aggregators. An aggregator&#39;s computer system then presents a ticket for each account it attempts to access. 
     In the detailed description of exemplary versions of the invention that follows, it is assumed that all parties have the necessary computers, hardware and software to access the Internet, utilize digital certificates, perform appropriate encryption, and process tickets utilizing methods described in this invention. 
     In step  201  of  FIG. 2A , relationships  202  are identified and established, if not already done so as described above, between a commerce web site, an aggregator web site and a customer. These relationships need only be established once and may be skipped (proceed to step  210  in  FIG. 2B ) if already established. As needs change, any of the steps  202  through  209  (in  FIG. 2B ) may be repeated in order to update the nature of the relationships. 
     In step  203 , a commerce web site obtains a digital certificate (if not already done) for use as an identity to create SSL encrypted sessions and digitally sign documents. Most Internet web server software includes the ability to utilize digital certificates and associated private keys. 
     In step  204 , an aggregator&#39;s web site similarly obtains a digital certificate (if not already done) for SSL authentication. Although strongly suggested, the invention does not require that the aggregator have a digital certificate, provided that a suitable alternate means exists for the commerce web site to authenticate the identity of the aggregator. 
     In step  205 , an aggregator must register an identity with each commerce web site that it intends to access. In most cases, this will require registering an aggregator&#39;s digital certificate with a commerce web site. Alternately, a commerce web site could issue some sort of password to each aggregator. In either case, the commerce web site must be able to identify the aggregator during each access to the commerce web site. 
     In step  206 , before an aggregator can access a customer&#39;s data, the customer must be known by the commerce web site. Typically, this will involve the customer joining an on-line shopping site, or signing up for on-line account access with a bank or brokerage house, for example. 
     In step  207 , the customer obtains a digital certificate from a certificate authority agreeable to both commerce and aggregator web sites, or otherwise establish an acceptable authentication among them. Preferably, commerce and aggregator web sites should be able to verify and trust the authenticity of the customer&#39;s digital certificate. 
     In step  208 , after all other relationships have been established, a customer registers an identity at an aggregator&#39;s web site. Typically, a customer will register his, hers, or its digital certificate with the aggregator. An aggregator may also issue some sort of password to each customer, however, this does not preclude the need, at least in this example, for each customer to possess a digital certificate. 
     In step  209 , shown in  FIG. 2B , the customer will inform the aggregator about each of his or her accounts at each commerce web site that he, she, or it wants the aggregator to access. This step may be repeated when the customer adds new accounts. 
     Steps  210  and beyond may be performed at any time, initiated by the aggregator&#39;s site autonomously of the customer, for example, or specifically requested by the customer initially as illustrated in step  209 . 
     In step  210 , if an aggregator has a ticket (electronic document) for a specific commerce web site, which is necessary to access a specific customer&#39;s accounts at that web site, then step  211  can be executed, otherwise, step  217  can be executed, as shown in  FIG. 2C . 
     In step  211 , a ticket optionally, but preferably, has at least two expiration date/time (“expiration time”) stamps, which can be one set by the commerce web site and the other set by the customer. Using the earlier or earliest expiration date/time stamp, it can be determined if the ticket has expired. In this regard, this exemplary version of the invention assumes that all computer systems involved in ticket processing use a unified time zone, such as UCT or GMT time zone, when comparing these date/time stamps. If the ticket has expired, step  216  can be executed, as shown in  FIG. 2C , otherwise step  212  can be executed. 
     In step  212 , an aggregator sends a copy of the ticket associated with the customer&#39;s accounts to a commerce web site for approval. 
     In step  213 , a commerce web site verifies the expiration date/time stamps, then verifies the digital signatures on the ticket. The ticket has at least two digital signatures—one for the commerce web site&#39;s portion of the ticket and another for the customer&#39;s portion of the ticket. Both digital signatures must prove or verify that both parties issued the ticket and that the ticket hasn&#39;t been tampered with. Finally, the commerce web site verifies that the ticket is associated with the aggregator requesting the account access. Assuming that all checks pass and the ticket is accepted, then step  214  can be executed, as shown in  FIG. 2B . Otherwise, step  216  can be executed, as shown in  FIG. 2C . 
     At step  214  in  FIG. 2B , the commerce web site permits the aggregator to access the customer&#39;s data. Assuming that steps  202  through  209  were skipped, it was not necessary for the customer to approve this particular access by the aggregator because the aggregator possessed a valid ticket. As long as the ticket remains valid, the aggregator will typically have unencumbered access to the customer&#39;s data, without additional approval from the customer. For this reason, expiration dates and times (if used) should be set to short, reasonable values. 
     The aggregator might access a customer&#39;s data at the commerce web site using screen scraping techniques, for example, where the data is extracted from data streams intended (by the commerce web site) to be displayed on a customer&#39;s browser. As an incentive to use this ticketing system, aggregators might be given a more formalized data feed utilizing XML, IFX, OFX or structured records, for example. 
     In step  215 , the aggregator closes the session with the commerce web site. Any further or future access starts over at step  201 . 
     In step  216  of  FIG. 2C , an aggregator has a ticket for a specific customer and a specific commerce web site, but it has been proven invalid. Since the ticket is no longer good, the aggregator purges it from data storage. 
     In step  217 , an aggregator does not have a ticket for a specific customer and a specific commerce web site, so it sends a request for a new ticket to the commerce web site. 
     In step  218 , the commerce web site creates a new ticket, which is merely a document with data fields for items on the ticket. Although not required by the invention, a document may be formatted with XML-style tags common with Internet documents. 
     In step  219 , the commerce site adds the aggregator&#39;s identification to the ticket. Since the aggregator has authenticated with the commerce web site, the identity may be obtained from the established session. This identity is used to validate the aggregator&#39;s access in step  213  of  FIG. 2B . A serial number (for auditing purposes) and the first expiration date/time (“expiration time”) can also be added to the ticket. The commerce web site may optionally add other fields to the ticket for its own use. 
     In step  220  of  FIG. 2D , using the Internet standard s/MIME encoding method, for example, the commerce web site then digitally signs the new ticket. The ticket is not yet complete, however, so the signature only covers those portions created by the commerce web site. The digital signature is created with the commerce web site&#39;s private encryption key. Anyone may verify the signature by accessing the digital certificate (and public key) associated with the signature. 
     In step  221 , using the Internet standard s/MIME encoding method, for example, the commerce web site then encrypts all or part of the new ticket using the customer&#39;s public key obtained from the customer&#39;s digital certificate. The commerce web site then forwards the new, encrypted ticket back to the aggregator in step  222 . 
     In step  223 , since only the customer has the private keys necessary to decrypt the ticket, the aggregator must forward the ticket for processing to the customer&#39;s computer system. If the customer is not currently accessing the aggregator&#39;s web site, step  224  is executed to wait for the customer. Otherwise, step  225  in  FIG. 2E  can be executed. 
     In step  224  of  FIG. 2D , an aggregator has a ticket that needs to be approved by the customer and wait for the customer to access the aggregator&#39;s web site. Thus, in step  225  of  FIG. 2E , the aggregator sends the new, encrypted ticket to the customer&#39;s computer system (such as by way of an Internet browser) and waits for the reply. 
     In step  226 , ticketing software running within the customer&#39;s browser uses the customer&#39;s private encryption key to decrypt the new ticket. The software also verifies the commerce web site&#39;s digital signature and any expiration date/time stamp. In step  227 , the customer is prompted to approve the ticket (see  FIG. 3  for an exemplary screen view). The prompt includes enough information to identify the aggregator, the commerce web site and the desired accounts. The prompt also includes the ability for the customer to adjust (shorten) the ticket&#39;s expiration date/time (“expiration time”). The ticket will often contain a second expiration date/time stamp for the customer. Also, the date/time stamp should be encoded with a single unified time zone, such as UCT or GMT, as mentioned above. The software should accordingly adjust the displayed expiration time to the customer&#39;s local time zone. Then, in step  228 , the prompt provides the customer with the ability to accept or reject the ticket requested by the aggregator (see  FIG. 3 ). 
     In step  229  of  FIG. 2E , the ticketing software running in the customer&#39;s browser adds the second expiration date/time (if such expiration times are used in the particular application) plus the customer&#39;s accept or reject status code to the ticket. In step  230  of  FIG. 2F , using the Internet standard s/MIME encoding method, for example, the ticketing software running in the customer&#39;s browser digitally signs the ticket using the customer&#39;s private encryption key. The ticketing software running in the customer&#39;s browser sends the completed ticket to the aggregator&#39;s web site n step  231 . 
     In step  232 , the aggregator can examine the accept or reject status code to determine if the ticket was approved by the customer. If the customer approved the ticket, step  210  can be executed, as shown in  FIG. 2B . Otherwise, step  233  is executed, indicating that the customer has rejected the aggregator&#39;s request for a new ticket, and the aggregator may not access the customer&#39;s accounts. 
     Possession and storage of tickets is typically the responsibility of the aggregator. Customers and commercial web sites usually do not need to store a copy of each ticket, although they may do so for diagnostic, auditing or other purposes. If an aggregator loses a ticket, though, there is no way to replace it. The aggregator must request that a new ticket be generated. 
     A commercial web site need only verify the validity of a ticket in order to authenticate an aggregator&#39;s access to a customer&#39;s data. This verification typically includes checking the digital signatures on the ticket against digital certificates maintained within a public key infrastructure. The signatures help ensure the authenticity of the ticket and that the ticket has not been tampered with. 
     Because ticket expiration is crucial to limiting account access, commercial web sites must check both expiration times on each ticket. Typically, but not necessarily, the earliest expiration time should determine when a ticket actually expires. Dual expiration times allow a customer and commerce web site to mutually agree upon the ticket&#39;s lifetime in a secure manner. 
     Although the exemplary usage scenarios presented in  FIGS. 2A through 2F  depict a single ticket for a given customer-web site-aggregator combination, more than one ticket might be used when varying levels of access are required. For example, one ticket might permit read-only inquiries about existing account transactions; and a second ticket might permit transactions to be initiated by an aggregator. Each ticket can have space for optional information to be inserted by the commercial web site and/or the customer that may be used to determine the type of access granted to a third party. 
     It is expected that all confidential communications among the customer&#39;s web browser, the aggregator, and the commercial web site will typically, but not necessarily, employ industry-standard SSL encryption. However, it is not necessary to securely store or encrypt a completed ticket because the ticket is bound to, and only works with, a specific customer, aggregator and commercial web site. A stolen ticket is of little value to anyone except the aggregator. Moreover, anyone can test the validity of a ticket. 
     Typically, ticket data, digital signatures and ticket encryption will be encoded into computer messages using standard Internet s/MIME encoding techniques. Internet s/MIME encoding has been widely adopted by most Internet mail, web browser and web server software. 
       FIG. 3  illustrates an exemplary situation where a customer prompts for a new ticket request, typically, but not exclusively, as described below. The customer is preferably given the ability to grant or deny the request and adjust the expiration time, if such times are used in a particular instance. Thus,  FIG. 3  merely illustrates one example of how the customer can be prompted. Any of a wide variety of other suitable programming dialogs known to those skilled in the art can also be used. 
     On customer screen  301 , a ticket request is usually processed and displayed by software running within a customer&#39;s Internet browser. This software may be incorporated by browser manufacturers or dynamically added to browsers with standard Internet applet technologies, such as Java or ActiveX, for example. Data fields  302  describing the parties and accounts involved with the ticket request are extracted from the ticket and displayed as part of the prompt. The customer can use a mouse (or similar pointing or other input device) to finish (close) the ticket request. 
     At  304 , the customer may adjust the ticket expiration date/time (If such expiration times are use in the particular application) by using a slider-style control with a mouse, for example. One skilled in the art will readily recognize that other input devices can be used for this and other customer responses. 
     At  305 , the customer chooses to either grant or deny access to the aggregator (agent). The default should typically be set to deny, so that the customer has to intentionally and affirmatively choose to grant access. When the customer chooses “Finished” at  303 , the results from this screen prompt are coded into the ticket, digitally signed or otherwise authenticated by the software running in the customer&#39;s browser and returned to the aggregator&#39;s web site. 
       FIG. 4  illustrates an exemplary simplified flow of the ticket processing, typically but not exclusively, as described below. 
     In step  401 , an aggregator web site  407  requests a new ticket to access customer accounts at a commerce web site  408 . 
     In step  402 , commerce web site  408  creates a new ticket, digitally signs it, encrypts it with the customer&#39;s public key and sends it to the aggregator  407 . 
     In step  403 , aggregator&#39;s web site  407  forwards the encrypted ticket to customer&#39;s computer  406  for approval. 
     In step  404 , web software in the customer&#39;s computer  406  decrypts the ticket, prompts the customer to adjust the expiration date/time, and prompts the customer to accept or reject the ticket request. The software then adds a second digital signature to the ticket and sends it back to the aggregator  407 . 
     At step  405 , the aggregator  407  can then use the ticket to securely access customer accounts at the commerce web site  408 . 
     One skilled in the art will readily recognize that this exemplary ticketing system provides a reliable, secure, reusable, tamper-resistant ticket that allows at least a specific third party (aggregator) to access to private or confidential customer data at various commercial web sites without knowledge of the customer&#39;s passwords. Furthermore, each reusable ticket can be set to expire at a customer-selected expiration time or one that is mutually agreed upon by both a customer and a commercial web site. The use of this ticketing system can also promote improved auditing of aggregator&#39;s activities at commercial web sites. The exemplary ticketing system can also leverage existing Internet and encryption technologies to allow for easy implementation. 
     The foregoing discussion discloses, and describes merely exemplary embodiments of the present invention for purposes of illustration only. One skilled in the art will readily recognize from such discussion, and from the accompanying drawings and claims, that various changes, modifications, and variations can be made therein without departing from the spirit and scope of the invention as defined in the following claims.