Fault Attack on the Authenticated Cipher ACORN v2

Algorithm 3

Require: A 99-bit differential string

Ensure: the fault locations

(1) Determine which category belongs to according to the position of its first 1

(2) Determine the candidates by comparing other locations of 1 appearing in

and using the making-the-most-use-of-things strategy

(3) if the number of candidates is 1  then

(4) return the unique candidate

(5) else

(6) for the keystream length extended to bits, from 1 to 64  do

(7) use the making-the-most-use-of-things strategy

(8) compare the extra locations of 1 appearing in

(9) if the number of candidates can be reduced to 1  then

(10) return the unique candidate

(11) end if

(12) end for

(13) if the number of candidates is still larger than 1  then

(14) use the high probability priority strategy to choose the location that the

string appears in the with the highest probability

(15) return the unique candidate

(16) end if

(17) end if