Abstract: Cryptography is the practise and study of techniques for secure communication in the presence of third parties. The necessity and the fact that exchanged messages are exposed to other people during the transmission promoted the creation of encryption systems, enabling just the recipients to interpret the exchanged information. In this paper, a particular cryptosystem called Rabin Cryptosystem is presented and analysed with the help of Chinese Reminder Theorem. Also, redundancy schemes for decryptions technique is mentioned and some basic mathematical concepts is explained and finally compared with RSA cryptosystem in terms of security and efficiency.