Robust Secure Authentication and Data Storage with Perfect Secrecy

Lecture 1 : Perfect Secrecy and Statistical Authentication

• Definition of perfect secrecy • One-time pad and optimality (Shannon's theorem) • Definition of statistical one-time MAC and construction. Historically, cryptography was treated as a practical problem with practical applications. Many of these schemes were insecure due to a lack of a mathematical foundation combined with no understanding of desirable properties in cryptography systems. Howeve...

Constructing Optimal Authentication Codes with Perfect Multi-fold Secrecy

We establish a construction of optimal authentication codes achieving perfect multi-fold secrecy by means of combinatorial designs. This continues the author’s work (ISIT 2009, cf. [1]) and answers an open question posed therein. As an application, we present the first infinite class of optimal codes that provide two-fold security against spoofing attacks and at the same time perfect two-fold s...

Authentication Schemes, Perfect Local Randomizers, Perfect Secrecy and Secret Sharing Schemes

Perfect Secrecy and Statistical

There are two key properties of the above. First, given only c, Eve should not be able to learn what m is. Second, Dec(Enc(m)) = m, so that Bob can accurately determine the message that Alice wanted to send. Creating functions Enc and Dec which satisfy this is a fundamental problem of cryptography. But given the above encryption scheme, knowing what these functions are is enough for anyone to d...

One-round Strongly Secure Key Exchange with Perfect Forward Secrecy and Deniability

Traditionally, secure one-round key exchange protocols in the PKI setting have either achieved perfect forward secrecy, or forms of deniability, but not both. On the one hand, achieving perfect forward secrecy against active attackers seems to require some form of authentication of the messages, as in signed Diffie-Hellman style protocols, that subsequently sacrifice deniability. On the other h...