  Copyright protection and authentication of digital contents has become a
significant issue in the current digital epoch with efficient communication
mediums such as internet. Plain text is the rampantly used medium used over the
internet for information exchange and it is very crucial to verify the
authenticity of information. There are very limited techniques available for
plain text watermarking and authentication. This paper presents a novel
zero-watermarking algorithm for authentication of plain text. The algorithm
generates a watermark based on the text contents and this watermark can later
be extracted using extraction algorithm to prove the authenticity of text
document. Experimental results demonstrate the effectiveness of the algorithm
against tampering attacks identifying watermark accuracy and distortion rate on
10 different text samples of varying length and attacks.
