The patient furnishes his identifier k₀ to the HAP and requests an EMR containing $a_1,\cdots ,a_n$ and linked to DID and k_b

D.1 Patient $\to$ HAP : k₀, DID, k_b, $a_1,\cdots ,a_n$

HAP challenges the patient to prove that he is the owner of k₀ and k_b

D.2 HAP $\to$ Patient : k₀, N_p

D.3 Patient $\to$ HAP : ${\left\{H\left(k_0,N_p\right)\right\}}_{k_0^{-1}},{\left\{H\left(k_b,N_p\right)\right\}}_{k_b^{-1}}$

HAP links DID to k_b and stores the result in Indy

D.4 HAP $\to$ Indy : DID, k_b, ${\left\{H\left(DID,k_b\right)\right\}}_{k_p^{-1}}$

HAP provides the requested EMR, protected by k, to the patient

D.5 HAP $\to$ Patient : $\underset{M}{\underbrace{DID,{\left\{EMR\right\}}_k}}$ , ${\left\{H\left(M\right)\right\}}_{k_p^{-1}}$ , ${\left\{k\right\}}_{k_0}$

Patient stores the requested EMR, protected by k, in his wallet

D.6 Patient $\to$ Wallet : $\underset{M}{\underbrace{DID,{\left\{EMR\right\}}_k}}$ , ${\left\{H\left(M\right)\right\}}_{k_p^{-1}}$ , ${\left\{k\right\}}_{k_0}$