Concept Development
THE CONCEPT
This project will be divided into two phases both using similar techniques to simulate a secure communication network. The first phase will demonstrate secure transmission and the second phase will simulate secure cloud storage. Both phases of the project work under the realistic assumption that an intruder is present and attempting to gain access.
THE EQUIPMENT
Shown below are the three major components used in this project:
FUNCTIONAL MODELING
PHASE 1
The detailed functional modeling shown in the figure above demonstrates the functions and processes in each step of the data transmission model. This project aims to securely transmit text and images. This can be extended to more advanced applications in the future depending on time availability. Therefore, the input is a text document or image at the transmitter's laptop. This will be sent as a binary data sequence which will then be split into four data packets. Each of the data packets will then undergo Reed Solomon encoding which will produce six data packets. After the encoding stage, the hacker will be introduced. The hacker's laptop will be connected to three of the six Raspberry Pi 2's. The output at the hacker’s laptop will be zero information, so long as no more than three out of six communication links are intercepted.
The six coded data packets will then act as an input to the receiver's laptop where they would be regrouped to produce one coded binary data sequence. This single coded data sequence will then be decoded at the receiver's laptop. The output of this process will be the same text document or image initially transmitted by the transmitter. This will demonstrate secure data transmission from transmitter to receiver after three out of six links have been compromised.
PHASE 2
The detailed functional modeling shown in the figure above shows the simulation of a cloud storage system that will encounter a hacker and multiple hard disk breakdowns. The transmitter and the receiver in this scenario are the same because the person storing the information will be the same person retrieving it. Therefore, in Figure 5, there is only a reference to a transmitter.
The input to this system is either a text document or an image which will be encoded at the transmitter's laptop. This will transform the information into a single long sequence of binary data bits. This sequence of data bits is split into four packets. These packets will then be Reed Solomon coded in a manner similar to that implemented in Phase 1 shown in Figure 4. At this stage a hacker's laptop will attempt to access three out of the six communication links using the Raspberry Pi 2's as entry points. Due to the splitter technique and the Reed Solomon coding, the hacker will be able to extract zero information provided that the threshold of three out of six links is not exceeded. The coded data will then be stored in six hard disks which will simulate cloud storage. The six packets are then retrieved from the hard disks where the transmitter's laptop will regroup the data packets into a binary data sequence that will be then decoded. This produces the output information which is the text document or image that the transmitter had initially stored.
PHASE I
In the first phase three RP's, operating on Linux, will be used as communication nodes. Each node will use Wi-Fi to connect the transmitter to the receiver. Each link will go through an RP which is an intermediate node. In reality, this function of the RP represents a node that could be located at any geographical location.
The coded information will be split evenly over the three links and will travel through each link via the RP nodes. A spy could have access to one or two of the links as seen below. A programmed splitter and Reed Solomon coding will guarantee the safety of the information. The aim is to have zero leakage for the spy and complete and correct transmission to the receiver. This plan was changed to use six links instead of 3 (See Functional Modeling for more information).
PHASE II
In the second phase six RP’s will be used instead of three. Instead of a “receiver” each RP will be connected to an external hard disk (currently USB flash drives) to imitate cloud storage. The transmitter will take a file and use the binary splitter to split it into 4 parts. RS encoding will be applied resulting in six packets. Each packet will be stored on a hard drive. RS coding will guarantee that the cloud still provides its service even if 2 out of the 6 disks are unplugged. Additionally, as seen below, if a spy has access to 3 out of 6 disks, he/she still will not be capable of deciphering transmitted information. After the development stage of this phase, the whole system will be tested including the splitter and Reed Solomon code.
RASPBERRY PI 2
Raspberry Pi (RP) is a low cost, small sized computer board, which can have a screen connected to it, and is easily programmable. It is for these reasons that we've chosen RPs as the central element to our project. It's low cost and small size is especially beneficial in the simulation phase where the RPs will behave as the nodes through which transmission occurs.
SONY EXTERNAL HARD DRIVE
External hardrives will be used for the storage phase of the project. The project simulation does not require an exceptionally large amount of data to be stored. This is why we will be using a hard drive with low storage space but high reputation in terms of reliability. This plan was changed. We've decided to use USB Flash drives instead as they're more compatible with the RPs.
NETGEAR WIRELESS ROUTER
As a precaution, we have chosen to use our own local wifi network when working on this project. This is done to avoid interfering or relying on TAMUQ's wifi.
