Abstract:
A spam resistant e-mail system employs communication via authenticated communication channels while providing a mechanism for rapidly growing a list of authenticated individuals and managing that list on a personal and collaborative basis to prevent spammers from joining the network.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of provisional applications 60/921,635; 60/921,636; and 60/921,637, all filed Apr. 2, 2007, and hereby incorporated by reference. 
     
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     BACKGROUND OF THE INVENTION 
       [0002]    E-mail or “electronic mail” is a computerized system for transmitting text messages and data files between identified individuals using the Internet. Most current e-mail systems use Simple Mail Transfer Protocol (SMTP), a default standard of the decentralized Internet community. 
         [0003]    E-mail offers considerable advantages over competing communication technologies such as telephone calls or facsimile transmissions. In contrast to telephone calls, e-mail does not require the availability of both parties at the same time and provides a text record that can be stored or forwarded. The equipment required for e-mail is more readily available and more flexible than that required for facsimile transmissions. The transmission of e-mail costs less and normally requires less human involvement than the transmission of a facsimile. 
         [0004]    While e-mail messages are reasonably secure and quickly transmitted from party to party, e-mail is plagued by bulk-transmitted, unwanted e-mail messages, known as “spam”. The Messaging Anti-Abuse Working Group (MAAWG), a consortium of Internet providers, estimates that in 2007, 85% of incoming e-mail is spam, with over 90 billion spam messages being sent a day. 
         [0005]    Currently, the problem of spam is managed principally through the use of filters at the e-mail recipient. These filters attempt to detect IP addresses or words commonly found in spam or use a blacklist identifying addresses transmitting spam. This former approach is error prone, while the blacklist is hampered by a sender&#39;s ability, under SMTP, to disguise his or her address (“spoofing”). 
         [0006]    This shortcoming of SMTP has led to the development of authentication systems for the SMTP protocol, for example, SMTP-AUTH or POP-before-SMTP. Generally such authentication systems have not been universally adopted, both because they require cooperation among many diverse parties and because the authentication process significantly limits an individual&#39;s freedom to communicate with any other individuals. 
         [0007]    Some estimate that spam currently costs businesses over $170 billion per year in lost productivity. Sophisticated spam filters and blacklisting systems can cost individuals $200 per year or more. 
       BRIEF SUMMARY OF THE INVENTION 
       [0008]    The present invention provides a spam resistant e-mail system that uses an authenticating Internet protocol and that allows rapid expansion and simple management of a list of authenticated users through the concept of personal “trusted human chains”. Each user manages a trusted human chain of other users with whom they may communicate and rapidly grows this chain by incorporating the trusted human chains of other individuals with whom communication is established. In this way the universe of potential correspondents grows extremely rapidly. A set of tools allows each individual to manage his or her human chain based on his or her own and the collective knowledge of the group of users. A successful, decentralized, dynamic list of non-spamming individuals is thereby created. The ability to easily curtail the efforts of spammers significantly limits the incentive to send spam, further limiting spam. 
         [0009]    One embodiment of the invention provides two additional, important features. The first is the use of standard SMTP e-mail addresses to identify individuals in the trusted human chain. This allows an almost seamless migration to the present system from standard e-mail. The second is the use of a pre-existing Internet standard having intrinsic authentication (intended for instant messaging) thereby eliminating a need to obtain wide scale adoption of a new Internet protocol. Specifically then, the present invention provides a spam resistant e-mail system having at least one e-mail managing computer connected to the Internet to communicate with users on user computers via an authenticated communication protocol. The e-mail managing computer and user computers execute stored programs to establish authenticated communications between the users and the e-mail managing computer and to allow each given user to form a given trusted human chain listing other member users. This given trusted human chain is recursively augmented to include other users linked to member users by trusted human chains of the member users. The system allows source-identified communication of e-mail messages between the given user and one or more specified users in the given user&#39;s augmented trusted human chain. 
         [0010]    It is thus a feature of one embodiment of the invention to provide for an authenticated e-mail system that rapidly expands to allow communication among a large number of individuals. Potentially, each individual trusted human chain quickly converges to all non-spamming individuals on the Internet, taking advantage of so called “small world phenomenon” postulating a linking of all connected individuals by a small number of links averaging about six. 
         [0011]    Each user in the augmented trusted human chain may be identified by an e-mail address of a SMTP e-mail system. 
         [0012]    It is thus another feature of one embodiment of the invention to allow easy migration from current e-mail systems (and current e-mail addresses) to the spam resistant e-mail system of the present invention and to allow their co-existence for an indefinite period of time. 
         [0013]    The system may communicate invitation messages using unauthenticated e-mail communications between the given users and potential users who have not established authenticated communications with the e-mail managing computer. These invitation messages allow the potential users to establish authenticated communications with the e-mail managing computer and to be added to the given user&#39;s augmented trusted human chain. 
         [0014]    It is thus another feature of one embodiment of the invention to use a highly scalable process, analogous to that of building the trusted human chains, to convert individuals to the spam resistant e-mail system. 
         [0015]    The system allows the given user to delete users from the augmented trusted human chain. 
         [0016]    It is thus a feature of one embodiment of the invention to enlist the individuals in the system as managers of spam sources and thus to create a decentralized and scalable system for identifying and removing spammers. 
         [0017]    The given user may identify a user to be deleted by selecting a message communicated to the user. 
         [0018]    It is thus a feature of one embodiment of the invention to provide a system for managing the trusted human chain that is as simple as identifying and deleting spam messages themselves. 
         [0019]    For each user in a trusted human chain, the e-mail system may store a join date of the user and the last date of communication by the user using the spam resistant e-mail system. This data is usable by the given user to manage the given user&#39;s augmented trusted human chain. 
         [0020]    It is thus a feature of one embodiment of the invention to provide the users with temporal data about the individuals in the trusted human chain and thereby to provide sophisticated management at the individual level either by manual action or rules effected by the individual. 
         [0021]    In addition or alternatively, the system may record a hierarchy of the users in the trusted human chains and statistics of deletions of users. Again this data may be available to the user in managing his or her trusted human chain. 
         [0022]    It is thus a feature of one embodiment of the invention to allow individuals to manage their trusted human chains taking advantage of the collective wisdom of the group and the relationships among members of the trusted human chain. 
         [0023]    In addition or alternatively, the system may record data describing a tree joining the users and may calculate a distance along this tree between any two users. 
         [0024]    Thus it is a feature of one embodiment of the invention to allow an individual user to manage his or her trusted human chain by controlling the number of degrees of separation defining his or her own chain or new chains added to his or her chain. 
         [0025]    The authenticated communications between the users and the e-mail managing computer may use an instant messaging protocol. 
         [0026]    It is thus a feature of one embodiment of the invention to make use of currently available authentication standards. 
         [0027]    The instant messaging protocol may be XMPP. 
         [0028]    It is thus another feature of one embodiment of the invention to make use of an approved Internet standard (IETF standard). 
         [0029]    When the system communicates an e-mail message between an originating user and one or more receiving users in the given user&#39;s augmented trusted human chain, the system may provide a link to an attachment to the e-mail message invocable by the receiving users to transfer attachment data from a stored file for the originating user to a stored file for the receiving users. This transfer may not occur until invocation of the link by the receiving user. 
         [0030]    It is thus a feature of one embodiment of the invention to eliminate the transfer of attachments for unwanted messages thus significantly decreasing Internet traffic. 
         [0031]    These particular features and advantages may apply to only some embodiments falling within the claims and thus do not define the scope of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0032]      FIG. 1  is a diagram showing communication between a user and an e-mail server of the present invention during authentication of the user; 
           [0033]      FIG. 2  is a flow chart of the authentication process of  FIG. 1 ; 
           [0034]      FIG. 3  is a diagram similar to that of  FIG. 1  showing the process of inviting a second user into a trusted human chain of the first user to form an initial trusted human chain; 
           [0035]      FIG. 4  is a flow chart showing the steps of the process of  FIG. 3 ; 
           [0036]      FIG. 5  is a set of tree diagrams depicting simple trusted human chains showing the aggregation process that occurs during the invitation process; 
           [0037]      FIG. 6  is a diagram similar to that of  FIG. 1  showing the communication of e-mail using the present invention between members of a trusted human chain; 
           [0038]      FIG. 7  is a flow chart showing the steps of  FIG. 6 ; 
           [0039]      FIG. 8  is a diagram similar to that of  FIG. 1  showing the transfer of an attachment to an e-mail message of the present invention; 
           [0040]      FIG. 9  is a fragmentary flowchart showing a step of virus detection possible in the present invention by the server; 
           [0041]      FIG. 10  is a screen display of an e-mail in-box provided by the present invention showing management of a trusted human chain by selection of a message; 
           [0042]      FIG. 11  is a tree-diagram similar to that of  FIG. 5  showing an individual&#39;s augmented trusted human chain together with data recorded for the members of the chain such as may be used to manage the trusted human chain; and 
           [0043]      FIG. 12  is a simplified screen display of a user control that may be used to manage the individual&#39;s trusted human chain. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0044]    Referring now to  FIG. 1 , the present invention provides a spam resistant network  10  including one or more e-mail managing computers  12 , typically servers, that may communicate with user-computers  14  operated by users  15 . The e-mail managing computers  12  and user-computers  14  are programmed to implement, between them, the protocols of the present invention. 
         [0045]    In this regard, the e-mail managing computer  12  will preferably provide for a number of Internet communication channels with the user-computer  14  including for example: a Web channel  18  allowing the exchange of HTTP protocol data, a file transfer channel  20  which may for example be the Web channel  18  or a channel using another protocol such as FTP, and an authenticated channel  22 . 
         [0046]    In the preferred embodiment the authenticated channel  22  uses the XMPP protocol (www.xmpp.org), an IETF standard instant messaging protocol that allows for authentication of text messages. More generally, because the authenticated channel  22  may be implemented readily between the e-mail managing computers  12  and the user-computers  14 , wide scale adoption of an IETF standard authentication protocol is not required and proprietary authentication systems could be used. 
         [0047]    In addition, although not explicitly indicated in the relevant figures, a data encryption layer, such as the Secure Socket Layer (SSL), can be readily added to all said communication channels to further improve the security and privacy levels of said channels. 
         [0048]    Referring also to  FIG. 2 , at a first step of the protocol of the present invention, the user  15  on user-computer  14  undertakes a first part of a registration process with the e-mail managing computer  12  through a website program  23  contained on the e-mail managing computer  12 . The user  15 , at this time, may contact the website program  23  using a standard browser on the user-computer  14  via the Web channel  18 . This website program  23  takes some identifying information about the user  15  and the user-computer  14  and may have the user  15  execute a legal agreement with respect to use of the spam resistant network  10  as indicated by process block  24 . 
         [0049]    At succeeding process block  26 , the user-computer  14  downloads an application program  28 , for example by file transfer channel  20 . This downloaded application program  28  is held in the user-computer  14  along with other programs  30  used by the user  15  including for example, the web browser and a standard SMTP e-mail system, and works together with the website program  23  to implement the steps of the present invention. 
         [0050]    Referring still to  FIGS. 1 and 2 , at succeeding process block  40  the registration process is completed by establishing additional data necessary to authenticate the user-computer  14  including a standard SMTP e-mail address and possibly including other authenticating information such as a unique Internet address or a serial number from a network interface card on the user-computer  14 . A time delay and/or a CAPTCHA or the like may be used to prevent automated registrations. This authentication may also assign to the user  15  a unique password or PIN number. The authentication process may allow the users to employ one or several computers using their pin numbers to establish their identity or by registering each particular computer individually. Preferably the authenticating information for each user  15  includes the standard SMTP e-mail address of the user  15 , a password selected by the user  15 , an optional screen name, and optionally other identifying data, for example, biometric data. Together this data provides a unique identification of the individual. The availability of such identity information enables users of the system to identify each other with a high degree of confidence, so as to mitigate or avoid the typical problems with phishing, pretexting and other forms of “social engineering” that are plaguing the current online communications. 
         [0051]    At this point the authentication process is complete and an authenticated channel  22  has been established for communication between the e-mail managing computer  12  and the user-computer  14 . The authenticated channel  22  operates to ensure that the user  15  (or the user-computer) is accurately identified in any communication between the user-computer  14  and the e-mail managing computer  12 . At any time after authentication, the user may log into the website program  23 , and after correctly identifying himself or herself, may edit or change this authentication information, as will be described further below. 
         [0052]    Referring to  FIG. 1 , the data from this authentication process is stored in a unique user file  42  generated by the server per process block  45 . Each user file  42  includes an identifier  44  of the user  15 , which in the preferred embodiment is a standard SMTP e-mail address of the user. The user file  42  also includes an e-mail buffer  46 , and attachment storage  48 , and a trusted human chain file  50  for that user  15  as will be described. 
         [0053]    Referring now to  FIG. 3 , initially the user  15  of the user-computer  14  will not be able to communicate with other users  15 ′ using the spam resistant network  10  which allows communication only with other authenticated users  15 ′. Each such authenticated user  15 ′ will be held in a list of such users  15 ′ within the trusted human chain file  50 , which is initially empty, or more accurately, is a trusted human chain consisting only of the user  15 . 
         [0054]    The user  15  must therefore populate the trusted human chain file  50 , that is, create an initial trusted human chain  53  of individuals who have been authenticated in the process described above with respect to process blocks  24 ,  26 ,  40  and  45  and are listed in the trusted human chain file  50 . Referring to  FIGS. 3 and 4 , for this purpose, the present invention allows the users  15  to send out invitation messages  51 , per process block  54 , by providing user SMTP e-mail addresses for other users  15 ′ over the Web channel  18  to the website program  23  or preferably by use of the authenticated channel  22 . 
         [0055]    At process block  56 , the e-mail managing computer  12  checks through all trusted human chains  53  in all user files  42  on its system to determine whether the invited user  15 ′ is already authenticated with the e-mail managing computer  12 , and thus on a trusted human chain of at least one user. If the result is affirmative, the e-mail managing computer  12  relays the invitation to the invited user  15 ′, who may react to the invitation per decision block  57 . Upon acceptance the user  15 ′ is added to the trusted human chain  53  of user  15  at process block  62  and the user  15  is immediately notified of this as indicated by process block  61  and may begin spam free communication with user  15 ′. Otherwise, the user  15 ′ is not added to the trusted human chain  53  of user  15 , and the user  15  is also notified at process block  61 . 
         [0056]    If at process block  56 , the user  15 ′ is not already in a trusted human chain  53  on the system, an invitation e-mail  51  is sent by the e-mail managing computer  12  (if the user is a “lone” user having no trusted human chain—typically because of a lapse in usage for an extended length of time), or a regular e-mail managing computer (if the user is not authenticated) that the user  15  has access to, using standard SMTP e-mail communication channels  52  as indicated by process block  58  to the user  15 ′ inviting him or her to join the trusted human chain of user  15 . 
         [0057]    The invitation e-mail  51  is received by the user  15 ′ via a standard e-mail program and may for example provide a link or URL to the website program  23  of the e-mail managing computer  12  with a text message inviting the user  15 ′ to join the spam resistant network  10 . The user  15 ′, reading the e-mail, may react by authenticating as described above with respect to  FIGS. 1 and 2  and as determined by decision block  59 . If the user  15 ′ declines or fails to joint the spam resistant network  10  after a predetermined period of time, the user  15  is notified per process block  61 . Otherwise, the user  15 ′ is added to the individual&#39;s trusted human chain (after authenticating themselves) as indicated by process block  62  and user  15  is notified at process block  61 . Note that after this authentication process user  15 ′ may also begin using the spam resistant network  10  for his or her own purposes. 
         [0058]    Referring now to  FIG. 5 , the adding of a user  15 ′ to the trusted human chain  53  of user  15  will normally also add those users  15 ″ on the trusted human chain  53  of the added user  15 ′. Thus, for example, the inviting user  15  may have a trusted human chain  53  including themselves (illustrated as node A) and two other individuals (illustrated as node B node C). The invited user  15 ′ (node D) may have a trusted human chain  53 ′ having two connected users  15 ″ (nodes E and F). At process block  62 , the connection of user  15  to a trusted human chain of user  15 ′ may merge the trusted human chain  53  to the trusted human chain  53 ″. The result is that trusted human chain  53  of user  15  becomes trusted human chain  53 ″ having node A with branches nodes B, C, and D, with node D having branches to nodes E and F. Likewise the invited user  15 ′ finds their trusted human chain  53  converted to a human chain  53 ′″ having node D with branches to nodes E, F, and A, with node A having branches to nodes B and C. These trusted human chains  53 ″ and  53 ′″ will be termed augmented trusted human chains. 
         [0059]    Referring now to  FIG. 6 , once an augmented trusted human chain  53  is produced, spam resistant e-mail communications may be made between any of the members of the augmented trusted human chain  53 . The e-mail message  66  may be sent using application program  28  by user  15  simply identifying a second user  15 ′ of user-computer  14 ′ by the standard SMTP address of that user. The method of generating and sending this e-mail message may appear identical to that provided by standard e-mail programs and may allow selection of a recipient through the use of a directory (displaying the contents of the user&#39;s trusted human chain  53 ) or by directly typing the address into the e-mail. The invocation of the spam resistant network  10  is automatic when the e-mail is composed using the application program  28  on the user-computer  14 . 
         [0060]    The e-mail message  66  using the spam resistant network  10  may include a text e-mail message  66  and possibly be associated with an attachment  68 . The text portion of the e-mail message  66  is sent via the authenticated channel  22 , thus assuring the recipient that the source of the e-mail (user  15 ) is accurately preserved and eliminating the possibility of spoofing. The attachment  68  may be sent by the channel  20  and is not directly authenticated but implicitly authenticated by association because it must be linked with (and accessed through) an authenticated e-mail message  66 . In this way authenticated instant messaging protocols such as XMPP may be used for standard e-mail functionality despite not being intended for this purpose and not having the ability to include attachments. This dual channel of transmission is provided by the application program  28  which simply automatically opens the second channel according to techniques understood in the art. 
         [0061]    The e-mail message  66  received by the e-mail managing computer  12  is placed in the e-mail buffer  46  of the user  15 . At the same time, a notification message  70  containing a portion of the text of the e-mail message  66  is forwarded via the authenticated channel  22  to the user  15 ′. The attachment  68  is placed in the attachment storage  48  of the user file  42  of user  15  and not transmitted further for the time being. The data of the e-mail buffer  46  and the attachment storage  48  of the user  15  is subject to an access control by the user  15 , meaning that the user  15  may establish permissions for access to this data. Normally the permissions will be set to allow access by the user  15 ′. The access control may allow the user  15  to, for example, grant both read and write accesses to attachments  68  to the user  15 ′ (or deny either), a benefit and flexibility that is not available under ordinary e-mail. 
         [0062]    As noted above, assuming that the destination user  15 ′ is on the trusted human chain  53  of user  15 , as indicated by process block  73  of  FIG. 7 , a notification message  70  is sent by authenticated channel  22  to user-computer  14 ′. At the recipient&#39;s user-computer  14 ′, a notification box  72  appears on the screen (shown enlarged to the right of the screen of computer  14 ′) providing the identifier  44  of the sending user  15  (which is reliable because it resulted from an authentication process) an excerpt or all of the short tests text message  74  contained in e-mail message  66 . The notification box  72  also provides accept and cancel buttons at  76 . 
         [0063]    It should be noted that at this point in time very little information has in fact been transmitted over the Internet to the user  15 ′, only enough to provide the notification box  72 . In the case of e-mails sent to multiple users, this approach vastly decreases the amount of traffic actually forwarded. 
         [0064]    At decision block  75 , the user  15 ′ may accept the e-mail message  66  by pressing the accept button, in which case, as indicated by process block  79  in  FIG. 7  and transfer arrow  77  in  FIG. 6 , the full text of the e-mail message  66  is transferred to the e-mail buffer  46  of the user file  42 ′ of the user  15 ′. At the same time as indicated by arrow  81  the attachment  68  is transferred to the attachment storage  48 ′ of the user file  42 ′ of user  15 ′ as indicated by process block  80 . 
         [0065]    If, upon the notification box  72  appearing the user&#39;s screen, the user  15 ′ presses the cancel button, the e-mail message  66  is refused and no further transmission to the user-computer  14 ′ occurs. The user  15  may receive a notification message to this effect. If the user  15 ′ does not reply to the notification block (for example because user-computer  14 ′ is not online) the notification is retained in the notification area of user&#39;s e-mail buffer  46 ′ and may be reviewed online by the user  15 ′ at a later time. The e-mail managing computer may be programmed to periodically send notification messages  70  to the user  15 ′ indicating that he or she has unread notifications. 
         [0066]    Referring to  FIG. 8 , the user may then periodically log into the user file  42 ′ for example using the HTTP channel  18  or other file transfer channel  20  to read the e-mail messages  66  that have not been responded to and respond to them by sending a reply e-mail message  66  or the like. The underlying e-mail message  66  of the notification may be forwarded in a similar fashion to that provided by normal e-mail using the spam resistant network  10 , and may be sent to a standard SMTP e-mail system by using a special option. At any time, the user  15 ′ may download the attachment  68  from the attachment storage  48 ′ using any secure protocol such as channel  20 . 
         [0067]    It will be understood that the present invention prevents the clogging of inboxes with unwanted attachments  68  even from accepted sources. Once the attachment  68  is accepted, however, the attachment exists in multiple copies in different user file  42 . This storage burden may be reduced on a given e-mail managing computer  12  by simply providing pointers to common data files for the attachments  68 . Alternatively multiple shadow copies of the files of the attachments  68  may be created and these multiple copies may be used as indicated by  FIG. 9  for the detection of viruses or corruption of the files by an inter-file comparison process  83  comparing files on various user files  42 . 
         [0068]    This feature of sending an attachment  68  to user  15 ′ by a transfer between user files  42  can significantly decrease Internet traffic in cases where users  15 ′ are clustered locally. Thus, for example, a first user  15  communicating with multiple recipient users  15 ′, the latter of which are clustered, may send the attachment  68  over the Internet only once and transfers to the multiple users  15 ′ may occur solely within the e-mail managing computer  12  shared by each of the users  15 ′, or with a localized peer to peer data transfer in which all participating peer computers  14 ′ are (1) authenticated with an e-mail managing computer  12  that is accessible to such user computers  14 ′, (2) are owned and operated by users  15 ′ who are members of the same Trusted Human Chains, and (3) are allowed to participate in such P2P transfers with the permission of users  15 ′. Should such a P2P scheme be activated, more robust and quicker data transfers for all participating user computers  14 ′, together with improved scalability of the e-mail managing computer  12 , may occur. 
         [0069]    It will also be understood that the present invention provides a solution to the problem of a user  15  inadvertently or inadvisably sending an e-mail or an attachment to user  15 ′ that the user  15  may wish to retract or modify. As noted above, so long as the user  15 ′ has not responded to a notification message, the bulk of the data of the e-mail remains in user file  42  of the user  15  where it is subject to access control by the user  15 . Accordingly the user  15  may simply change the permission of this data to deny access e-mail even after it is sent (but before it is reviewed by the user  15 ′) to effectively retract that e-mail and the attachments. 
         [0070]    This retention of control of the data by the user  15  may be further exploited to allow modification of the e-mail message  66  and the attachment  68 , invisibly to the user  15 ′, to effect a correction of that data. This mechanism further allows an automatic notification to the user  15  as to whether the e-mail has been reviewed by the user  15 ′, i.e. a “return receipt”. 
         [0071]    The present invention rapidly populates a human chain  53  for any user  15  and in fact with as few as six levels or degrees of separation a trusted human chain  53  can theoretically encompass a number of individuals approximating the number of non-spamming individuals on the Internet. This rapid scalability also creates the risk of incorporating spamming individuals, however, and therefore the user is provided with tools to manually or automatically manage their trusted human chains  53 . 
         [0072]    Referring now to  FIG. 10 , at a most basic level each user  15  is given the ability to delete other users from their trusted human chain  53 . In a preferred embodiment, this may be accomplished most easily when the user  15  is reviewing his or her e-mail buffer  46  which may as illustrated provide at least two columns: a first column  92  providing names of the sources of notifications (in the preferred embodiment being SMTP e-mail addresses) and the second column  94  providing subject lines or snippets of the text message. For each row, the user may invoke a submenu  96 , for example, by right clicking on a mouse. The submenu  96  provides a set of menu choices including reading the e-mail message  66  (which like a standard e-mail system opens the e-mail and displays icons of the attachments), deleting the e-mail message  66  (which deletes the e-mail from the e-mail buffer  46 , and deleting the user (which deletes the sender of the e-mail from the user&#39;s trusted human chain  53 ). In this way, if a spam sender should slip into the trusted human chain he or she may be simply removed. 
         [0073]    Importantly, the present invention also provides more sophisticated trusted human chain management tools that may be implemented manually by the user or through a set of user-invoked rules created by the user or previously prepared and accessible from a menu. Referring to  FIG. 11 , an example trusted human chain  53  includes eleven nodes labeled A-I. Each node of the trusted human chain  53  is linked to a database record holding the node&#39;s parent node such as is necessary to reconstruct the tree hierarchy shown in  FIG. 11 . Each node also contains the identifier  44  of the user represented by the node, the time  95  that the user joined the trusted human chain, and the time  97  of the user&#39;s last communication using the spam resistant network  10 . A program implemented in the present invention also calculates additional data that may be useful in managing the trusted human chain  53  including a distance  98  between the top node (the user who owns the trusted human chain  53 ) and any other given node, and a “pollution index” calculated as the number of nodes  100  within the trusted human chain  53  that have been deleted by the given user owning the trusted human chain  53  or other users in other trusted human chains. Thus, for example, node E. connects to four nodes F, G, H, and I, two of which have been deleted by the user or other users (for example in other trusted chains). Thus, the pollution index for node E. is 0.5 indicating that half of the members in the chain having a root node of E have been deleted by some individual. Other pollution indexes may be created based on this principle. 
         [0074]    Using this recorded data for the trusted human chain  53 , the user  15  may create a set of rules governing how his or her trusted human chain  53  will grow. For example, using the time data the user  15  may eliminate individuals from his or her trusted human chain  53  who have not communicated on the spam resistant network  10  in over a year to weed out possibly abandoned addresses. The distance calculation may be used, for example, to limit the absolute size of the trusted human chain or when an aggregation of two trusted human chains  53  is being performed, to take only the top level or top few levels of the trusted human chains  53  of individuals invited into the user&#39;s network. The pollution index may be used to prevent aggregation with trusted human chains  53  that are highly polluted, excepting only the user  15 ′ who is invited and not the trusted human chain  53  of the user  15 ′. 
         [0075]    In this way the users  15  may absolutely manage their trusted human chains  53 , may apply rules and techniques to limit the growth of their trusted human chains  53 , and by using authenticated channel  22  may avoid problems of spoofing. The authentication process and the inability of spammers to operate successfully on the network will both limit existing spammers and the motivation of new spammers to join the spam resistant network  10 . The system is readily adaptable to charging a small fee for the transmission of the e-mail, an approach that eliminates the principal benefit of spamming, that is having low per mailbox transmission cost. 
         [0076]    As noted above, any user  15  may log onto the website program  23  after they have been authenticated, and change their authenticating information. For example, the user  15  may wish to change their SMTP e-mail address based on a change in e-mail provider. Such changes may be automatically communicated to all other individuals  15 ′ in the user&#39;s trusted human chain  53  and in particular may automatically update the user&#39;s directory provided by the present invention (functionally equivalent to contact lists in standard SMTP e-mail). Because of the authentication process underlying the present invention, such an ability to edit the user&#39;s screen name or other authenticating particulars presents very little risk to the integrity of the trusted human chain  53 . On the other hand it provides great flexibility for the user to change his or her conventional e-mail address or screen name, for example. The ability to automatically and safely correct other user&#39;s directories allows the present invention to be used to provide all users with up-to-date lists of conventional e-mail addresses for the individuals in their trusted human chains  53  as those e-mail addresses may change with changes in employment or the like. 
         [0077]    While human chains are used for some peer-to-peer type file sharing systems, these systems are intended to preserve anonymity among users, contrary to the very purpose of an e-mail system which provides reasonably secure and private communication between specified individuals. 
         [0078]    The present invention has been described in terms of the preferred embodiment, and it is recognized that equivalents, alternatives, and modifications, aside from those expressly stated, are possible and within the scope of the appending claims.