CIAA principles of security # We have already outlined these principles in Sicurezza delle reti and talked about the concepts of authentication and integrity. Here we try to deepen these concepts and delve a little bit more on the attack vectors. This note mainly focuses on the…
Public Key Encryption # We now define a formally what is a public key encryption Formal definition of Public Key Encryption # We define a 3-tuple formed as follows: ( G , E , D ) where G is the generator for the private and public keys, from now on identified as ( p k , s k )…
Utilizzano blocchi per cifra invece che stream generators. n bits in input and m bits in output generally a key is expanded into multiple keys, one for each rounds, and applied to a round function that iterates on the m . DES 56 bit 3DES 56*3 bit di chiave AES che può andare a…
Introduzione a Crittografia # al corso di crittografia di Christof Paar su Youtube, con aggiunte del corso Unibo. Classifications and definitions # Classification nowadays as many many applications like, and it’s a increasing important field Cryptology (2) # La branca…
XOR operation # È una operazione binaria abbastanza semplice però ci sarà importante per andare ad analizzare dei cifrari di un certo genere. Come il ONE TIME PAD che faremo fra poco in OTP and Stream Ciphers. Teorema cifratura con XOR # Prendiamo X una variabile aleatoria in {…
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 )…
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…
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.…
In this note we will talk about some common ways to attack wireless based devices. Attacking an automated door # Usually these doors are opened by radio frequency keys, and can be opened easily (e.g. replay attacks, Jam the frequency) Jamming # This is the easiest way to attack.…
First time we talked about this was in Sicurezza delle reti#Protocollo SSL But that was a simple toy model. Secure Socket Layer # Secure socket Layer and TLS add security (see security principles in Notions of Security ) on the transport layers, whereas IPSec protocol adds it to…