Seyyed Mohammad Reza Hashemi - Young Researchers and Elite Club, Qazvin Branch, Islamic Azad University, Qazvin, Iran,
Mohammad Mahdi Deramgozin - Young Researchers and Elite Club, Qazvin Branch, Islamic Azad University, Qazvin, Iran,
M. Hajighorbani - Young Researchers and Elite Club, Qazvin Branch, Islamic Azad University, Qazvin, Iran,
Shabnam Safari - Department of Computer ,Zagros Institute of Higher Education, Kermanshah, Iran

Due to the efforts up to the present time, encryption methods in different contexts with various shapes of writing don’t have the same performance and there is the necessity of some researches in order to get to the mature status. In this paper we describe and compare several text watermarking algorithms such adding space between words zero-width, watermarking with the use of inserting the connector and the separator character, the grouping text characters watermarking method, watermarking with the help of different shapes of characters of different fonts and adding invisible characters in Latin texts.

identity recognition, manipulation detection, digital texts, watermarking