Book excerpt: Modern cryptology, which is the basis of information security techniques, started in the late 70's and developed in the 80's. As communication networks were spreading deep into society, the need for secure communication greatly promoted cryptographic research. The need for fast but secure cryptographic systems is growing bigger. Therefore, dedicated systems for cryptography are becoming a key issue for designers. With the spread of reconfigurable hardware such as FPGAs, hardware implementations of cryptographic algorithms become cost-effective. The focus of this book is on all aspects of embedded cryptographic hardware. Of special interest are contributions that describe new secure and fast hardware implementations and new efficient algorithms, methodologies and protocols for secure communications. This book is organised in two parts. The first part is dedicated to embedded hardware of cryptosystems while the second part focuses on new algorithms for cryptography, design methodologies and secure protocols.