(IJCSIS) International Journal of Computer Science and Information Security, Vol. 9, No. 1, 2011
documents to differentiate spam from necessary documents and apply rule based routing. The users also have the provision of triggering an automated SharePoint work flow process to ensure that fax documents go to the right folders or destinations while filtering junk out of the system. Another article [7] criticized the spam filters for their application in content sorting only. Moreover, most of the spam filters sort the spam after accepting the messages. High volume of spam forbids the users from receiving it and all messages classified as spam are automatically deleted. This causes difficulties to genuine senders as their messages are deleted without any reason being assigned. Using spam filter on protocol level would reject the spam and assign reason for doing so. Such spam filters are rare. This article advocated the use of pdf format over spam filters to counter spam faxes. A suggestion was made regarding using secure fax (S/FAX) over IP to generate secure mails in pdf format containing sender’s name, address, and digital signature. This pdf can also be given password protection, if required. Upon receipt, the pdf reader can verify the integrity of the document as well as the digital signature and allow the receiver to either view it or discard as spam. An article [11] suggested charging fax spammer from $500 to $1500 for every unsolicited fax they send. The article added that this amount could become significant if fax spammers send many faxes. The recipient needs to keep track of all unsolicited faxes with date & time stamps to be used for claims. A technology [6] has also been proposed regarding spam fax filter that can transform a rasterized form of a fax image into non-rasterized forms. Non-rasterized forms of the fax image can then be checked against spam fax characteristics, or characteristics of fax images not known as spam. The fax image is declared as spam if it tests favorably to at least one of the known characteristics of spam fax. In case, the fax image doesn’t conform to any of the characteristics of spam fax, it can be declared as non spam. Another article [12] suggested complaining to regulator and highlighting the matter to draw mass attention to curb the fax spam menace. VIII.
TABLE I. Technologies
Mechanism
Filtering / Segregation
Load on Network Disposal
Response Time
Comparative Analysis Integration of FoIP with SharePoint Inbound rule base routing of fax into SharePoint sites Searching content, metadata tags and OCR features of fax documents to filter spam from necessary fax documents High After fax enters the system High
IX.
S/FAX over IP (PDF Format) Use of S/FAX over IP to generate secure mails in pdf Verifying integrity and digital signature of pdf documents to allow fax messages to enter
Spam Fax Filter (Non- rasterized Format) Conversion of rasterized form of fax image into non-rasterized form Verifying nonrasterized forms of the fax image against spam fax characteristics to filter spam from necessary fax documents.
Low Before fax enters the system Low
High After fax enters the system High
CONCLUSION
S/FAX over IP approach proposed by Engelbert is conclusively better than rest of the approaches, as this approach does not allow the spam fax to get into system. Rather, this approach proposes to use spam filter to accept or discard fax messages subject to verification of integrity and digital signature of incoming fax messages. Also, this approach proposes to assign reasons for rejection of fax messages enabling the senders to receive the status of their messages. X.
LIMITATIONS
The researcher experienced certain limitations while conducting this research as there is no benchmark available, which could be taken into consideration for comparing the technical approaches to prevent spam in fax over IP. The researcher interacted with fax users to understand their expectations from these spam prevention approaches to identify the key indicators for comparison. The researcher attached high significance to pre disposal of spam faxes as this would prevent the spam faxes from entering into the system. The significant factors may be different for different users.
COMPARATIVE ANALYSIS
A comparative analysis as given in table.I involving three approaches [1], [6], [7] has been done to understand the unique characteristics associated with each approach. While comparing, the key indicators such as disposal of spam faxes, system overload, response time etc were kept in consideration. The researcher had attached higher significance to anti fax spam technology offering pre disposal of spam faxes as this would largely save the network from getting flooded with spam faxes resulting in higher load on resources.
XI.
FUTURE RESEARCH WORK
The researcher is willing to work and explore this area more in order to identify best technologies and approaches to prevent spam in fax over IP. The researcher also intends to bring more technologies and approaches under the ambit of comparisons. A detailed research can be initiated on the basis of already covered issues and suitable statistical parameters can be used for rigorous technical comparisons. Developing a globally acceptable technology or approach to prevent spam in fax over
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