5. Conclusion

Cryptography has defined the notions of security and proved the safety of cryptosystems, message authentication codes and digital signatures. In addition, higher-level protocols, such as secure communications and electronic voting systems, have been designed.

Today, cryptography is trying to design more secure and efficient systems, such as those that guarantee integrity and confidentiality by passing over the clear message only once, instead of once to encrypt it and then again to guarantee the integrity of the encrypted message. Finally, not all adversary models have yet been defined. Today, real-world attacks are carried out either on protocols that have not been proven secure, or because the adversary model does not reproduce the real world. In some smart cards, for example, the adversary can access information on the secret key from observations on computing...