Covering the specific issues related to developing fast block ciphers using software and hardware implementation, this book provides a general picture of modern cryptography. Covered is the meaning of cryptography in informational society, including two-key cryptography, cryptographic protocols, digital electronic signatures, and several well-known single-key ciphers. Also detailed are the issues concerning and the methods of dealing with designing fast block ciphers and special types of attacks using random hardware faults.