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QuestionIn a Hierarchical Deterministic (HD) wallet, keys ar

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QuestionIn a Hierarchical Deterministic (HD) wallet, keys are derived in a… Image transcription textkm Km. 2 Km, 1 Kmo Km, 2,0 Km, 2,1 Km,2,2 Km,0,0 Km,0, 1 Km,0,2 km, 1,0 Km, 1,1 Km, 1,2 Figure 2.1… Show moreIn a Hierarchical Deterministic (HD) wallet, keys are derived in a tree structure such that a parent key can derive a sequence of children keys. Each child key can then derive a sequence of grandchildren keys, and so on, to an infinite depth. See Figure 2.1.To simplify the process, let’s assume that the arrows in Figure 2.1 represent hash computations, i.e.:km,0 = Hash(km || 0), km,0,0 = Hash(km,0 || 0), km,0,1 = Hash(km,0 || 1),1 = Hash(km || 1), km,1,0 = Hash(km,1 || 0), km,1,1 = Hash(km,1 || 1) etc….It is straightforward to notice that as long as a user possesses the master key km, the user can derive all children and grandchildren keys. In retrospect, if a user possesses km,0, then he/she can only derive the grandchildren keys under km,0 but not those under km,1.Figure 2.2 shows a different construction.In this construction, a user first generates pseudorandom values for all k and l. After that, the user calculates x and y values as follow:x3,1 = k3,1 ? Hash(k3,2 || l3,1)y2,2 = k2,2 ? Hash(k3,2 || l2,2)x2,1 = k2,1 ? Hash(k2,2 || l2,1)y2,1 = k2,1 ? Hash(k3,1 || l2,1)…and so on, where ? is an exclusive-OR operation. In other words, the general formulas are given by:xi,j-1 = ki,j-1 ? Hash(ki,j || li,j-1) andyi-1,j = ki-1,j ? Hash(ki,j || li-1,j).All the k values are secret information. All the x, y, and l values are public information. Note that this approach is different from Figure 2.1 because now, a user in possession of k2,1 can derive all the keys ki,j for i = 2 and j = 1 using only k2,1 and the public x, y, and l values.Show how a user in possession of k1,1 can use this key and the public values to obtain k1,0, k0,1, and k0,0.Analyse the security of this design. In particular, discuss if it is possible for someone in possession of k2,1 to derive higher level keys such as k3,1, k2,2, or k3,2. Justify your answers.(Hint: You will need to refer to the property of the exclusive-OR operation and the properties of a hash function.) (14 marks)Image transcription textX3.1 X3.0 K3.0 & /3,0 K3.1& 13,1 K3,2 & /3,2 y2.1y2.2 y2.0 X2.1 X2.0 K … Show more… Show moreComputer ScienceEngineering & TechnologyInformation SecurityFINANCE FIN387

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