by srihari.kadali

1. Netaji Institute of Engineering & Technology
Dept of Computer Science and Engineering
A Project on
A Secure Erasure Code-based Cloud Storage
System with Secure Data Forwarding
By Under The Guidance of
SRIHARI KADALI Mr.P.Darshan (H.O.D & professor)

2. Content
Abstract
Existing System
Demerits
Proposed System
Architecture
Merits
Functional Requirements
Non Functional Requirements
System Design
Screen Shots
References

3. Abstract
The main technical contribution is that the proxy re-encryption
scheme supports encoding operations over encrypted messages as well
as forwarding operations over encoded and encrypted messages. Our
method fully integrates encrypting, encoding, and forwarding.
Implementing threshold proxy re-encryption and decentralized erasure
code.
Distributed storage System used for distribution purpose, and it
depends on the secure storage system.
Storage server and key server are used.
Parameters are more flexible adjustment between servers(storage and
key).

4. Existing System
General encryption schemes protect data confidentiality, but also limit
the functionality of the storage system because a few operations are
supported over encrypted data. Storing data in a third party’s cloud
system causes serious concern on data confidentiality.
General encryption scheme for storing data.
DES algorithm is used for key generation.
For the storage data ,user has to manage his keys .
Single storage server for whole file.

5. Existing System

6. Disadvantages Of Existing System
There are three problems in the above straightforward integration of
encryption and encoding. First, the user has to do most computation
and the communication traffic between the user and storage servers
is high. Second, the user has to manage his cryptographic keys.
Communication traffic between the user and storage servers.
User’s device of storing the keys is lost.
Storing and retrieving, it is hard for storage servers .
Only one time encryption using general encryption schemes.

7. Proposed System
The method of threshold proxy re-encryption.
Decentralized erasure code method can be used for distributed
storage system.
Distributed storage system depends on the secure cloud
storage.
Storage server and key server those two systems used for
storage system.
Encryption using Blowfish algorithm.

8. Architecture

9. Advantages Of Proposed System
By using the threshold proxy re-encryption scheme, we present a
secure cloud storage system that provides secure data storage and
secure data forwarding functionality in a decentralized structure
Data is more confidential.
Highly protected by an security mechanism of the Server
Easy distribution and data forwarding.
Less Time consuming.

10. Functional Requirement
Encryption
Re-encryption
Storage
Decryption

11. Non Functional Requirement
Privacy
Reliability
Scalability
Performance
Security

12. System Design
Workflow Diagram
A workflow diagram visually represents the movement and transfer
of resources, documents, data and tasks through the entire work process for
a given product or service.
Use case Diagram
Use case diagrams are used to describe a set of actions use cases that
some system or systems subject should or can perform in collaboration
with one or more external users of the system actors.
Sequence Diagram
A sequence diagram is a kind of interaction diagram that shows how
processes operate with one another and in what order.

13. Workflow Diagram

14. Use Case Diagram

15. Sequence Diagram
Login Register Home File select
jButtonActionPerformed
Register to
cloud
jButtonActionPerformed
Select file for encryption
Encryption
jButtonActionPerformed
jButtonActionPerformed
jButtonActionPerformed

16. Continue…
Re-encryptionSplitting
Select No. of tokens
jButtonActionPerformed
Upload file
jButtonActionPerformed
Select VM1 and VM2
Retrieve
jButtonActionPerformed
Receiving from
VM1 and VM2
Decryption
jButtonActionPerformed

17. Modules
Process Encryption
Threshold-Proxy Function
Secure Cloud Storage
Data Forwarding
Data Retrieval

18. Login and Registration

19. Encryption Process

21. // Creation of Secret key
byte key[] = "HUFEdcba".getBytes();
String k = key.toString();
SecretKeySpec secretKey = new SecretKeySpec(key, "Blowfish");
// Creation of Cipher objects
Cipher encrypt = Cipher.getInstance("Blowfish");
encrypt.init(Cipher.ENCRYPT_MODE, secretKey);
// Open the Plaintext file
cis = new CipherInputStream(fis, encrypt);
// Write to the Encrypted file
byte[] b = new byte[1024];
int i = cis.read(b);
while (i != -1) {
fos.write(b, 0, i);
i = cis.read(b); }
fos.flush();
fos.close();
cis.close();
fis.close();
String fenc = " File Encrypted ";
JOptionPane.showMessageDialog(null, fenc);
count++;
Coding

22. Splitting Process

23. Threshold Proxy Re-encryption Scheme
// Creation of Secret key
byte key[] = "abcdEFUH".getBytes();
SecretKeySpec secretKey = new
SecretKeySpec(key,"Blowfish");
// Creation of Cipher objects
Cipher encrypt = Cipher.getInstance("Blowfish");
encrypt.init(Cipher.ENCRYPT_MODE,
secretKey);

24. Selecting Servers For Files

25. Secure Cloud Storage

26. Server Side File Receiving

27. int bytesRead;
int current = 0;
ServerSocket serverSocket = null;
serverSocket = new ServerSocket(7777);
while(true) {
Socket clientSocket = null;
clientSocket = serverSocket.accept();
InputStream in = clientSocket.getInputStream();
OutputStream output = new
FileOutputStream("C:/"+filename+".zip");
byte[] buffer = new byte[1024];
while ((bytesRead = in.read(buffer)) != -1) {
output.write(buffer, 0, bytesRead);
}
Coding

29. try
{
Socket sock1 = new Socket("192.168.0.154", 7777);
// sendfile
File myFile = zipFile1;
System.out.println(zipFile1);
byte[] mybytearray = new byte[(int) myFile.length()];
FileInputStream fis = new FileInputStream(myFile);
BufferedInputStream bis = new BufferedInputStream(fis);
bis.read(mybytearray, 0, mybytearray.length);
OutputStream os = sock1.getOutputStream();
os.write(mybytearray, 0, mybytearray.length);
os.flush();
sock1.close();
String sen="Files are forwarded to cloud Storage server 1 !!!";
JOptionPane.showMessageDialog(null,sen);
jTextArea1.append("Sending File:"+z1);
jTextArea1.append("Files are forwarded to cloud Storage server 1 !!!");
}
catch(Exception e)
{
System.out.println("Exception : "+e);
}
Coding

30. File Retrieval Process

31. try
{
int bytesRead;
int current = 0;
ServerSocket serverSocket1 = new
ServerSocket(4000);
while(true) {
Socket clientSocket = serverSocket1.accept();
InputStream in = clientSocket.getInputStream();
String op="D:/secure/server1/server1.zip";
OutputStream output = new
FileOutputStream(op);
//jTextArea1.append("Received File Location from
Server1:"+output);
byte[] buffer = new byte[1024];
while ((bytesRead = in.read(buffer)) != -1) {
output.write(buffer, 0, bytesRead);
}
in.close();
output.close();
String ip2="192.168.1.2";
jTextArea1.append(" Server1 IP Address:"+ip2);
jTextArea1.append("Received File Location from
Server 2:"+op);
String fr=" File can be Received from Server1.";
JOptionPane.showConfirmDialog(null,fr);
serverSocket1.close();
}
Client Sending Filename
Cipher

32. Cipher Cipher

33. try
{
Socket sock = new Socket("192.168.1.2",4000); //client IP address
jTextArea1.append("n Client IP :"+sock);
// sendfile
String fn= "D:"+reqfile1+".zip";
File myFile = new File(fn);
jTextArea1.append("n File location :"+myFile);
byte[] mybytearray = new byte[(int) myFile.length()];
jTextArea1.append("n File Length :"+mybytearray);
FileInputStream fis = new FileInputStream(myFile);
BufferedInputStream bis = new BufferedInputStream(fis);
bis.read(mybytearray, 0, mybytearray.length);
OutputStream os = sock.getOutputStream();
os.write(mybytearray, 0, mybytearray.length);
os.flush();
String sen="Files are forwarded to Client !!!";
JOptionPane.showMessageDialog(null,sen);
os.close();
sock.close();
}
Coding

34. Cipher
Server Sending Files to Client

35. try
{ Socket sock = new Socket("192.168.1.2",4000); //client IP
address
jTextArea1.append("n Client IP :"+sock);
// sendfile
String fn= "D:"+reqfile1+".zip";
File myFile = new File(fn);
jTextArea1.append("n File location :"+myFile);
byte[] mybytearray = new byte[(int) myFile.length()];
jTextArea1.append("n File Length :"+mybytearray);
FileInputStream fis = new FileInputStream(myFile);
BufferedInputStream bis = new BufferedInputStream(fis);
bis.read(mybytearray, 0, mybytearray.length);
OutputStream os = sock.getOutputStream();
os.write(mybytearray, 0, mybytearray.length);
os.flush();
String sen="Files are forwarded to Client !!!";
JOptionPane.showMessageDialog(null,sen);
os.close();
sock.close();
}
catch(Exception e)
{
System.out.println("Exception : "+e);
Coding

37. try {
String sourcefile = "D:/secure/server1/server1.zip";
File sf=new File(sourcefile);
if (!sourcefile.endsWith(".zip")) {
System.out.println("Invalid file name!");
System.exit(0);
} else if (!new File(sourcefile).exists()) {
System.out.println("File not exist!");
System.exit(0);
}
ZipInputStream in =new ZipInputStream(new
FileInputStream(sourcefile));
ZipFile zf = new ZipFile(sourcefile);
int a = 0;
for (Enumeration em = zf.entries(); em.hasMoreElements();) {
String targetfile = em.nextElement().toString();
ZipEntry ze = in.getNextEntry();
out = new FileOutputStream("D:/secure/EXTRACT/" + targetfile);
byte[] buf = new byte[1024];
int len;
while ((len = in.read(buf)) > 0) {
out.write(buf, 0, len);
} a = a + 1;
}
if (a > 0) {
JOptionPane.showMessageDialog(null, "Files are unzipped, click
NEXT");
jTextArea1.append("nServer1 Files can be Extractedn");
jTextArea1.append("ZipFile Name:"+sf.getName()+"n");
jTextArea1.append("ZipFile size :"+sf.length()+"n");
String fol="D:/secure/EXTRACT";
File folder=new File(fol);
jTextArea1.append("n Files in the Path:n"+folder.getAbsolutePath());
}
out.close();
in.close();

38. try { String p=a;
String s11="plaintxt"+l;
String s12="des"+l;
String key1 ="AbCd124"+l;
l++;
File kkk=new File(p);
BufferedReader br=new BufferedReader(new FileReader(kkk));
jTextArea1.append("nnGiven File Name is:"+kkk.getName()+"
System.out.println("Given File Name is:"+kkk.getName()+"n");
jTextArea1.append("Given File size is:"+kkk.length()+"n");
System.out.println("Given File size is:"+kkk.length()+"n");
File dec= new File("D:/secure/firstDEcryption/"+s11+".txt");
FileInputStream fis = new FileInputStream(p);
FileOutputStream fos = new FileOutputStream(dec);
CipherOutputStream cos = null;
jTextArea1.append("Decrypted File Name is:"+dec.getName()+"n");
System.out.println("Decrypted File Name is:"+dec.getName()+"n");
jTextArea1.append("Decrypted File Path is:"+dec.getAbsolutePath()+"
jTextArea1.append("Key To Decrypt the cipher Text:"+key1);
System.out.println("Decrypted File Path is:"+dec.getAbsolutePath()+"n"
// Creation of Secret key
byte key[] = "abcdEFUH".getBytes();
SecretKeySpec secretKey = new SecretKeySpec(key,”Blowfish");
// Creation of plain objects
Cipher decrypt = Cipher.getInstance("DES");
decrypt.init(Cipher.DECRYPT_MODE, secretKey);
// Open the ciphert file
CipherInputStream cis=new CipherInputStream(fis, decrypt);
// Write to the decrypted file
byte[] b = new byte[1024];
int i = cis.read(b);
while (i != -1) {
fos.write(b, 0, i);
i = cis.read(b);
}
fos.flush();
fos.close();
cos.close();
fis.close();
}

39. try{
int j;
/** Takes all files in a specified directory and merge
them together...*/
File firstDEcryption = new
File("D:/secure/firstDEcryption/");
listOfFiles = firstDEcryption.listFiles();
for( j=0; j<listOfFiles.length; j++){
String lines;
String srcFile = listOfFiles[j].getPath();
outFile = "D:/secure/merging.txt";
of=new File(outFile);
BufferedReader inFile=new BufferedReader(new
FileReader(new File(srcFile)));
BufferedWriter outPut=new BufferedWriter(new
FileWriter(outFile, true));
String fil=listOfFiles.toString();
jTextArea1.append("Files to be Merged:"+fil);
jTextArea1.append("Merged File Path:"+outFile);
while((lines=inFile.readLine()) != null) {
outPut.write(lines);
outPut.newLine();
}
String fenc=" Files can be Merged ";
JOptionPane.showMessageDialog(null, fenc);
outPut.flush();
outPut.close();
inFile.close();
} }

40. Re-Decryption Process

41. Integrated a newly proposed threshold proxy re-encryption
scheme and erasure codes over exponents.
The threshold proxy Re-encryption scheme supports
encoding, forwarding, and partial decryption operations in a
distributed way.
By using the threshold proxy re-encryption scheme, we
present a secure cloud storage system that provides secure
data storage and secure data forwarding functionality in a
decentralized structure.
key servers act as access nodes for providing a front-end layer
such as a traditional file system interface.
Conclusion

42. References
IEEE 2012 paper on Distributed and Parallel systems, “A secure
Erasure code based Cloud storage System with Secure Data
forwarding”.
Swings (second Edition) By Matthew robinson and Pavel
vorobiev.
www.youtube.com
Fast Software Encryption, Cambridge Security Workshop
Proceedings (December 1993), Springer-Verlag, 1994, pp. 191-
204. IEEE Paper.