🛡️Cybersecurity

Metodi di key exchange Trusted Key parties (sono come Certificate authorities studiati in Sicurezza delle reti) Merkle Puzzles DH protocol Trusted Third parties Squared Key problem Un problema abbastanza ovvio è che per storare le chiavi di tutti c’è una necessità $O(n^{2})$ on $O(n)$ users Se c’è un trusted key parties il numero delle chiavi si riduce di molto, ritorna ad essere lineare! Protocols Toy Exchange protocol TTP = Trusted Third party (simile a quanto poi si avrà in Asymmetric Cryptography) ...

First of all, we need to have a strong understanding of how a program allocates memory during its execution. See Memoria, Memoria virtuale and other notes about Nomi e Scope, Gestione della memoria. The thing you have to remember is that Every new function call allocates a new block, with his local variables. How the calling parameters are stored in the stack How the heap is allocated (common heap algos are in Gestione della memoria) How the stack grows (and how it can overflow it, and overwriting important data). Common attack vectors We use C, as it is the easiest way to show how this could be attacked. ...

Some notes Mix-based systems Created in 1981 by David Chaum. Very similar to the previous one, in practice, in the end, it acts as a proxy but not only does it take and receive, but it also mixes together the packets it has received from the sources, applying its key. Disadvantage: The public-private mixing system is very slow. For this reason, a network of nodes is established, each having a symmetric key, making it much faster. ...