Summary
In this chapter, we have analyzed hash functions, digital signatures, and blind signatures. After introducing hash functions, we started by describing the mathematical operations behind these one-way functions followed by an explanation of SHA-1. We then explained digital signatures with RSA and ElGamal with practical numerical examples and examined the possible vulnerabilities.
Finally, the blind signature protocol was introduced as a cryptographic instrument for implementing electronic voting and digital payment systems.
Therefore, you have now learned what a hash function is and how to implement it. You also know what digital signatures are, and in particular, you got familiar with the signature schemes in RSA and ElGamal. We also learned about the vulnerabilities that could lead to digital signatures being exposed, and how to repair them.
Finally, you have learned what blind signatures are useful for and their fields of application.
These topics are essential...