An Efficient Two-Factor Authentication Scheme Based on the Merkle Tree

. 2020 Oct 9;20(20):5735. doi: 10.3390/s20205735

Algorithm 2: MOTP generation.

Input:

h a s h T r e e, s u b H e i g h t, r a n d o m L i s t, g e n e r a t e d T i m e

Output: OTP

t i m e M i n u s \leftarrow n o w () - g e n e r a t e d T i m e

;

i, j \leftarrow g e t P o s (t i m e M i n u s)

;

r a n d o m \leftarrow g e t R a n d o m (j, r a n d o m L i s t)

;

o t p \leftarrow h a s h M u l t i T i m e s (r a n d o m, p - i - 1)

;

p r o o f \leftarrow g e t P r o o f (j, h a s h T r e e, s u b H e i g h t)

;
return

{o t p + p r o o f}

;