2
Recommended Elliptic Curve Domain Parameters over
F p
Page 13
n
=
01
00000000
00000000
00000000
0001DCE8
D2EC6184
CAF0A971
769FB1F7
h
=
01
2.6.2
Recommended Parameters secp224r1
The veriﬁably random elliptic curve domain parameters over
F p secp224r1 are speciﬁed by the sex-
tuple T
=
(p ;a ;b ;G;n ;h ) where the ﬁnite ﬁeld
F p is deﬁned by:
p
=
FFFFFFFF
FFFFFFFF
FFFFFFFF
FFFFFFFF
00000000
00000000
00000001
=
2224
 296
+1
= x3
The curve E: y2
+ax
+b over
F p is deﬁned by:
a
=
FFFFFFFF
FFFFFFFF
FFFFFFFF
FFFFFFFE
FFFFFFFF
FFFFFFFF
FFFFFFFE
b
=
B4050A85
0C04B3AB
F5413256
5044B0B7
D7BFD8BA
270B3943
2355FFB4
E was chosen veriﬁably at random as speciﬁed in ANSI X9.62 [1] from the seed:
S
=
BD713447
99D5C7FC
DC45B59F
A3B9AB8F
6A948BC5
The base point G in compressed form is:
G
=
02
B70E0CBD
6BB4BF7F
321390B9
4A03C1D3
56C21122
343280D6
115C1D21
and in uncompressed form is:
G
=
04
B70E0CBD
6BB4BF7F
321390B9
4A03C1D3
56C21122
343280D6
115C1D21
BD376388
B5F723FB
4C22DFE6
CD4375A0
5A074764
44D58199
85007E34
Finally the order n of G and the cofactor are:
n
=
FFFFFFFF
FFFFFFFF
FFFFFFFF
FFFF16A2
E0B8F03E
13DD2945
5C5C2A3D
h
=
01
2.7
Recommended 256-bit Elliptic Curve Domain Parameters over
F p
This section speciﬁes the two recommended 256-bit elliptic curve domain parameters over
F p in this
document: parameters secp256k1 associated with a Koblitz curve, and veriﬁably random parameters
secp256r1.
Section 2.7.1 speciﬁes the elliptic curve domain parameters secp256k1, and Section 2.7.2 speciﬁes the