Encryption Decryption

2. TABLE OF CONTENT
 Introduction
 Text Encryption
 Text Decryption
 Feasibility-Study
 Methodology
 Purpose of Project
 System Requirements

3. INTRODUCTION
Encryption
The process of converting plaintext into
ciphertext.
Decryption
The process of converting ciphertext into
plaintext.

4. METHODOLOGY

5. PURPOSE OF PROJECT
 Provides security
 File encryption
 Communication encryption
 Network traffic encryption
 Password manager
 Single sign-on

6. ALGORITHM USED
RSA
MD5
SHA
DH

7. RSA RIVEST-SHAMIR-ADLEMAN
Private-Key Cryptography
 Key is shared by both sender and receiver
 if the key is disclosed communications are compromised
 also known as symmetric, both parties are equal
 hence does not protect sender from receiver forging a message &
claiming is sent by sender
Public-Key Cryptography
 uses two keys – a public key and a private key
 asymmetric since parties are not equal
 uses clever application of number theory concepts to
function
 complements rather than replaces private key cryptography

8. 0 LEVEL DFD FOR RSA

9. MD5 (MESSAGE-DIGEST)
• It performs very fast on 32-bit machine.
• MD5 is being used heavily from large corporations, such as IBM,
Cisco Systems, to individual programmers.
• MD5 is considered one of the most efficient algorithms currently
available.

10. 0 LEVEL DFD FOR MD5

11. SHA (SECURE HASH ALGORITHMS)
• SHA-1 or Secure Hash Algorithm 1 is a cryptographic hash function which
takes an input and produces a 160-bit (20-byte) hash value.
• To calculate cryptographic hashing value in Java, MessageDigest Class
is used, under the package java.security.

12. 0 LEVEL DFD FOR SHA

13. DH DIFFIE-HELLMAN
If you want a simpler plain English explanation
of DH that can be readily understood by even
non-technical people,
There is the double locked box analogy.
• Alice puts a secret in a box and locks it
with a padlock that she has the only key
to open.
• She then ships the box to Bob.
• Bob receives the box, puts a second
padlock that only he has the key to on it,
and ships it back to Alice.
• Alice removes her lock and ships the box
to Bob a second time.
• Bob removes his lock, opens the box,
and has access to the secret that Alice
sent him.

14. 0 LEVEL DFD FOR DH

15. SYSTEM REQUIREMENTS
Software Requirements
 Turbo C & C++ and Dev-C
 Works on Windows 7, XP, Vista and 8
 Works on 64 bit Windows & 32 bit Windows
 Mac OS X 10.3 and above
Hardware Requirements
 Intel Pentium 4 or above
 Floppy-Drive • CD-ROM drive
 10 GB of free hard-disk
 keyboard and mouse
 RAM(minimum 512 MB)