The updated version of Stallings' Cryptography and Network Security is now available from Pearson. Security is essential at a time of worldwide computer fraud, electronic eavesdropping, and viruses. The aim of this book is to present a realistic examination of both the theory and application of network security and cryptography. By offering a tutorial and overview of cryptography and network security technology, the book's first section explores the fundamental concerns that network security capability must address. The practise of network security?practical applications that have been put in place and are currently being used to offer network security?is covered in the book's second half.