The document describes a system for detecting word substitution in text to identify hidden meanings. It discusses the existing problem of suspicious emails not being detected. The proposed system uses algorithms like fuzzy string matching and cosine similarity to match words in emails to a database of suspicious words and detect if any words have been substituted. It was able to implement a system to block harmful emails but has limitations like only matching to words in the database and not considering context. Future work could make it more accurate by adding more words and features to the system.

1. Submitted by-
Abhishek Bansal
9911103404(F5)
Jaypee Institute of Information Technology, Noida

2. Introduction
Current Open Problem
Problem Statement
Background Study
Requirement Specification
Algorithms Used
Use Case Diagram
Limitations
Conclusion
Future Work

3.  Text substitution or textual obfuscation is the
art of substituting one word in place of some
another word. It helps in hiding the actual
meaning of the text. Text substitution means
replacing the words which attract attention
like threat or danger by words which are
normal and do not attract attention.
Substitution replaces words that are, or may
be, on the watch list by more innocuous
words, making the message seem more
“ordinary” and so likely to be not selected for
further analysis.

4. In the existing system, the mails are sent
to the authenticated users who are
intended to be received.
Some defects in existing system are-
 Suspicious mails cannot be detected.
 Offensive users cannot be identified.

5. To counter terrorism and to identify such
acts and prevent them from happening I
studied “Detecting word substitution in
text” through which the actual hidden
meaning of the message can be known.

6. List of all Sources
 Wikipedia
 IEEE Xplore Digital Library
 Acm digital library
 Springer Journals
 International Journal od Advanced
Research in Computer Science and
Software Engineering etc

7. Hardware requirements
Processor : Pentium 2.4 GHz or above
Memory : 256 MB RAM or above
Cache Memory: 128 KB or above
Hard Disk : 3 GB or above [at least 3mb of
free space required]
Software requirements
Operating System : Windows 7 and above

8. Fuzzy String Matching
Sentence Oddity
Cosine Similarity

10. Data base of suspicious words needs to be
updated regularly
Words are matched only for the ones
present in database.
Words are not checked in what context
they are written.
A target word is selected in a sentence to
check whether it has been substituted in
text or not.

11.  I was able to implement a system which blocks
emails that contains words which are not safe and
are harmful in nature by matching with the words
already present in the database and detecting
words which might have been replaced by some
other words to make the sentence normal. This
can be helpful in preventing activities which can
affect the society in a bad way. By analyzing the
emails which contain such words the information of
the person can also be obtained and illegal acts
can be prevented from happening.

12.  This application is capable of producing the
desired output. It currently uses words
already selected for checking whether it has
been substituted or not. And the current
system could also be made more accurate by
adding more words and updating the data
base regularly. Also some other features like
feature extraction can also be implemented
which will further help to classify the emails.
Using information science can further improve
the accuracy of the results.

13. THANK YOU