Datasheet

Table Of Contents
43.3.6.11.4 Parameters Definition
Table 43-85. ZpEcDsaGenerateFast Service Parameters
Parameter Type Direction Location Data Length Before
Executing the
Service
After
Executing
the Service
nu1ModBase nu1 I Crypto
RAM
u2ModLength + 4 Base of
modulus P
Base of
modulus P
nu1CnsBase nu1 I Crypto
RAM
u2ScalarLength
+ 8
Base of Cns Base of Cns
u2ModLength u2 I Length of
modulus P
Length of
modulus P
nu1ScalarNumber nu1 I Crypto
RAM
u2ScalarLength
+ 4
Scalar Number
used to multiply
the point A
Unchanged
nu1OrderPointBase nu1 I Crypto
RAM
u2ScalarLength
+ 4
Order of the
Point A in the
elliptic curve
Unchanged
nu1PrivateKey nu1 I/O Crypto
RAM
u2ScalarLength
+ 4
Base of the
Private Key
Unchanged
nu1HashBase (see
Note 1)
nu1 I Crypto
RAM
u2ScalarLength
+ 4
Base of the
hash value
resulting from
the previous
SHA
Unchanged
u2ScalarLength u2 I Length of scalar
(same length as
the length of
order)
Length of
scalar
nu1PointABase (see
Note 2)
nu1 I/O Crypto
RAM
3*u2ModLength
+ 12
Input point A
(three
coordinates
(X,Y) affine and
Z = 1)
Resulting
signature
(R,S,0)
nu1ABase nu1 I Crypto
RAM
u2ModLength + 4 Parameter a of
the elliptic curve
Unchanged
nu1Workspace nu1 I Crypto
RAM
8*u2ModLength
+ 44
Corrupted
workspace
Note: 
1. The hash value calculus is defined by the ECDSA norm and depends on the elliptic curve domain
parameters. To construct the input parameter, the 4 Most Significant Bytes must be set to zero.
2. The resulting signature format is different from the point A format (see Description above for
information on the point A format).
SAM D5x/E5x Family Data Sheet
Public Key Cryptography Controller (PUKCC)
© 2019 Microchip Technology Inc.
Datasheet
DS60001507E-page 1533