Merge eSign Default with airSlate SignNow

Merge esign default

okay welcome to the second talk in this session which is on information combining differential fault attacks on default by marcin marcia lagueller christopher browning maria isada and marcel is giving the talk thank you for the introduction today i want to be i will be talking about differential fault attacks on the default block cipher so first of all i will start with some background information on what differential fault attacks are and how the default block server tries to protect against them and then with armed with that knowledge we will show some attacks on the initial version of this block cipher with the simple key schedule and next up we will consider what happens if the conditions of the simple key schedule are no longer given and we have the we have um independent round keys and finally based on this knowledge that of equivalent keys that i will get to uh we will show some attacks on the strong schedule as proposed in the final design so let's start with some background on differential fault attacks so maybe someone some of you remember uh differential crypt analysis where the idea is that you have two messages with a given difference that lead to a certain internal difference delta t with some probability p and based on this expected difference we can then try to recover the key by guessing parts of the final round key and seeing whether we observe this expected difference when we perform differential fault attacks we do something different but this time we start with the same message twice and we then in one of the computations we disturb the computation by using some by physically affecting the operating conditions of the device for example by glitching the clock or disturbing the power supply or something like that and this would induce a fall during computation and we can then use this fault or difference in computation to perform a very similar key recovery attack as in differential cryptanalysis so maybe we i want to talk about this fault attack a bit in a bit more detail so here is a zoomed in version of what we have seen just now so there would be one s box of the final after final round and in the fault model proposed by the designers of the default block cipher um they said that an attacker can flip one arbitrary bit during one computation and if the attacker can flip one arbitrary bit they are able to introduce induce a certain difference delta in and then they will observe a certain difference delta out based on the difference in the in this ciphertext nibble and with this transition you can actually limit the number of values for u and v and with this limited space for u and v you also limit the space for the key and this is essentially the idea of differential fault attacks to recover the key using much less...