Fp72 =Fp24 [z]/(z3−w),/wa non-cube and z3= 21/24
Each rational point P5∈G2⊂E(Fp72 )has a special
vector representation with 72 elements in Fpfor each
x5and y5coordinates. The construction below show
that point P5∈E(Fp72 )and its cubic twisted iso-
morphic rational point P4∈E(Fp24 ), which also has
a quadratic twisted isomorphic rational point P′′′ ∈
E(Fp12 ), that lead to a more quadratic twisted iso-
morphic rational point P′′ ∈E(Fp6)and its cubic
twisted isomorphic rational point P′∈E(Fp3)and
P∈E(Fp).
P5(x5, y5) = ((a, 0, ..., 0),(0, ..., 0, b)) /x5, y5∈Fp72
P4(x4, y4) = ((a, 0, ..., 0),(0, ..., 0, b)) /x4, y4∈Fp24
P′′′(x′′′ , y′′′ ) = ((a, 0, ..., 0),(0, ..., 0, b)) /x′′′, y′′′ ∈Fp12
P′′(x′′ , y′′ ) = ((a, 0, ..., 0),(0, ..., 0, b)) /x′′, y′′ ∈Fp6
P′(x′, y′) = ((a, 0,0),(0,0, b)) with x′, y′∈Fp3
P(x, y) = (a, b)with x, y ∈Fp
The cost of multiplication, squaring and inversion in
in the 72th twisted field Fp72 are:
M72 = (M24)Fp3= (M12)Fp2)Fp3= ((M6)Fp2)Fp2)Fp3
= (((M3)Fp2)Fp2)Fp2)Fp3= (((6m)Fp2)Fp2)Fp2)Fp3
= (((6M2)Fp2)Fp2)Fp3= (((18m)Fp2)Fp2)Fp3
= ((18M2)Fp2)Fp3= ((54m)Fp2)Fp3= (54M2)Fp3
= (162m)Fp3= 162M3= 972m.
S72 = (S24)Fp3= (S12)Fp2)Fp3= ((S6)Fp2)Fp2)Fp3
= (((S3)Fp2)Fp2)Fp2)Fp3= (((5s)Fp2)Fp2)Fp2)Fp3
= (((5S2)Fp2)Fp2)Fp3= (((10m)Fp2)Fp2)Fp3
= ((10M2)Fp2)Fp3= ((30m)Fp2)Fp3= (30M2)Fp3
= (90m)Fp3= 90M3= 540m.
I72 = (I24)Fp3= (I12)Fp2)Fp3= ((I6)Fp2)Fp2)Fp3
= (((I3)Fp2)Fp2)Fp2)Fp3
= (((9m+ 2s+i)Fp2)Fp2)Fp2)Fp3
= (((9M2+ 2S2+I2)Fp2)Fp2)Fp3
= (((35m+i)Fp2)Fp2)Fp3
= ((35M2+I2)Fp2)Fp3= ((109m+i)Fp2)Fp3
= (109M2+I2)Fp3= (331m+i)Fp3
= 331M3+I3= 1997m+ 2s+i.
Exploring the sixth path
E(Fp)→E(Fp3)→E(Fp6)→E(Fp12 )→E(Fp36 )→E(Fp72 )
The appropriate choices of irreducible polyno-
mial defined by:
Fp3=Fp[u]/(u3−β),with βa non-cube and u3= 2
Fp6=Fp3[v]/(v2−u),with va non-square and v2= 21/3
Fp12 =Fp6[t]/(t2−v),with ta non-square and t2= 21/6
Fp36 =Fp12 [w]/(w3−t),with wa non-cube and w3= 21/12
Fp72 =Fp36 [z]/(z2−w),/za non-square and z2= 21/36
Each rational point P5∈G2⊂E(Fp72 )has a special
vector representation with 72 elements in Fpfor each
x5and y5coordinates. The construction below show
that point P5∈E(Fp72 )and its quadratic twisted
isomorphic rational point P4∈E(Fp36 ), which also
has a cubic twisted isomorphic rational point P′′′ ∈
E(Fp12 ), that lead to a more quadratic twisted iso-
morphic rational point P′′ ∈E(Fp6)and its cubic
twisted isomorphic rational point P′∈E(Fp3)and
P∈E(Fp).
P5(x5, y5) = ((a, 0, ..., 0),(0, ..., 0, b)) /x5, y5∈Fp72
P4(x4, y4) = ((a, 0, ..., 0),(0, ..., 0, b)) /x4, y4∈Fp36
P′′′(x′′′ , y′′′ ) = ((a, 0, ..., 0),(0, ..., 0, b)) /x′′′, y′′′ ∈Fp12
P′′(x′′ , y′′ ) = ((a, 0, ..., 0),(0, ..., 0, b)) /x′′, y′′ ∈Fp6
P′(x′, y′) = ((a, 0,0),(0,0, b)) with x′, y′∈Fp3
P(x, y) = (a, b)with x, y ∈Fp
The cost of multiplication, squaring and inversion in
in the 72th twisted field Fp72 are:
M72 = (M36)Fp2= (M12)Fp3)Fp2= ((M6)Fp2)Fp3)Fp2
= (((M3)Fp2)Fp2)Fp3)Fp2= (((6m)Fp2)Fp2)Fp3)Fp2
= (((6M2)Fp2)Fp3)Fp2= (((18m)Fp2)Fp3)Fp2
= ((18M2)Fp3)Fp2= ((54m)Fp3)Fp2= (54M3)Fp2
= (324m)Fp2= 324M2= 972m.
WSEAS TRANSACTIONS on COMPUTER RESEARCH
DOI: 10.37394/232018.2022.10.17
Ismail Assoujaa, Siham Ezzouak, Hakima Mouanis