From a technical standpoint, Nigerian Email Cybercrime is rather challenging. Whilst the rest of the world tries to engineer technical controls to filter incoming unsolicited email, Nigeria is faced with the rather usual task of controlling massive amounts of outgoing unsolicited email. Most available technologies today, are not designed to address outgoing Email such as the ones we see in the case of Nigeria.

Traditionally, spammers reside outside the external Network, although some might try to harvest internal Network resources to convey or relay their messages, SPAM traffic is generally seen as incoming traffic of an external nature. Hence, most technologies combating unsolicited mail, tend to address it as undesirable incoming mail.

The solution for the Nigerian Outgoing Email 419, is a reverse engineering of unsolicited email technologies, that filters these email from leaving it’s source address. In the case of Nigeria, the primary source is the Nigerian ISP.

Nigerian unsolicited email leaves the Nigerian ISP in two forms, A) As regular SMTP Email, B) As HTTP Web Based mail. An effective solution needs to address both types of unsolicited mail formats to be effective.

The Solution

The 419 Email Solicitation System is an advanced Network System, that inspects both outgoing Email and HTTP packets, performs Paul Graham’s Spam Filter bayesian statistical analysis (See http://www.paulgraham.com/spam.html), and than makes a decision on denying or granting a particular Outgoing Email or Http Request.

The Nigerian 419 Email will consist of the following component:

A) Packet Re-assembly
B) Bayesian Statistical Classification Component
C) Decision Component
D) Spam database
E) Non Spam Database

The System should also be integrated with other unsolicited technologies such as:
A) RBL Blocking System (IP Black list database).
B) OPEN RELAY Testing System.

Conceptual Level 0 Diagram From Nigerian 419 System



Packet Re-Assembly Component

The Packet Re-assemble module separates outgoing SMTP and HTPP packets and combines them into individual whole messages. There will be two types of messages. Email and HTTP requests. Each type of message will be stored into separates Database, and then forwarded to the Bayesian Classification component.

Bayesian Classification Component

The Bayesian Classification model uses the training Data in the 419 and non-419 database to assign a probability weight to each individual message, and classifies the message as 419 or none 419. Http://www.stat.rutgers.edu/~madigan/PAPERS/sagtu.pdf)

Decision Component

The Decision Component evaluates the weighted probability of individual HTTP and SMTP messages, discards those with probabilities of being 419 messages and forward Non-419 messages. Denied messages will be granted appropriate feedback, either in the form a browser message, or in the form of an email non-delivery report.

Filtering at the Centralized Internet Exchange Model

A consortium of African Internet Service Providers,have been actively lobbying for centralized Internet Exchange Points (IXP). The IXP’s are centralized InternetService Points, where national ISP’s can collectively source Internet connectivity and distribute it to their customers.

The most efficient level of content filtering can be implemented at these IXP’s, just for the fact of the
centralized model(http://www.afrispa.org/initiatives.htm) . However, IXP’s in Nigeria are still conceptual, the limitations of this model includes; economic feasibility and general infrastructure limitations such as consistent electricity and the availability of an integrated fiber optics network. The author suggests the implementation of IXP’s include 419 filtering solutions for HTTP as well as SMTP traffic in regions with high Cyber crime traffic.

Nevertheless the prime issue with this model is feasibility. “In Nigeria, there are three companies engaged in the production of telecommunication cables using imported copper and other local resources like poly vinyl chloride materials for insulation. There is no company that is cuurently producing fibre optic cables in the country. The copper cable producing companies are producing only low pair capacity of 50, 100, 200 pairs. There is need for a plant that will produce high pair capacity cables that will enhance massive provision of lines to the teaming population.” (http://www.nigeriaembassyusa.org/investment.shtml). Filtering at the ISP, might not be feasible for some years to come.

BENEFITS OF THE 419 SYSTEM

The Anti-419 System such as the one proposed above has many benefits.

A) It will deny SMTP and HTTP 419 Emails from leaving Nigerian ISP.
B) It can be implemented anywhere at the ISP’s Internal Network.
C) It can be implemented as a hardware solution

Please note, that a reputable American Company has agreed to design this product. Questions for the author regarding the product can be mailed to Yeyerolli1@aol.com  .