RFC 5639, "Elliptic Curve Cryptography (ECC) Brainpool Standard Curves and Curve Generation", March 2010

Errata ID: 2082
Status: Verified
Type: Technical
Publication Format(s) : TEXT
Reported By: Alfred Hoenes
Date Reported: 2010-03-21
Verifier Name: Nevil Brownlee
Date Verified: 2013-03-16

Section A.2, pg. 25 says:

|  1.  Set h = find_integer_2(s).
|
|  2.  Convert h to an integer A.

   3.  If -3 = A*Z^4 mod p is not solvable, then set s = update_seed(s)
       and go to Step 1.

   4.  Compute one solution Z of -3 = A*Z^4 mod p.

   5.  Set s = update_seed(s).

   6.  Set B = find_integer_2(s).

   7.  If B is a square mod p, then set s = update_seed(s) and go to
       Step 6.

   8.  If 4*A^3 + 27*B^2 = 0 mod p, then set s = update_seed(s) and go
       to Step 1.

   9.  Check that the elliptic curve E over GF(p) given by y^2 = x^3 +
       A*x + B fulfills all security and functional requirements given
       in Section 3.  If not, then set s = update_seed(s) and go to Step
       1.

   10. Set s = update_seed(s).

   11. Set k = find_integer_2(s).

   12. Determine the points Q and -Q having the smallest x-coordinate in
       E(GF(p)).  Randomly select one of them as point P.

It should say:

|  1.  Set A = find_integer_2(s).
|
   2.  If -3 = A*Z^4 mod p is not solvable, then set s = update_seed(s)
       and go to Step 1.

   3.  Compute one solution Z of -3 = A*Z^4 mod p.

   4.  Set s = update_seed(s).

   5.  Set B = find_integer_2(s).

   6.  If B is a square mod p, then set s = update_seed(s) and go to
       Step 5.

   7.  If 4*A^3 + 27*B^2 = 0 mod p, then set s = update_seed(s) and go
       to Step 1.

   8.  Check that the elliptic curve E over GF(p) given by y^2 = x^3 +
       A*x + B fulfills all security and functional requirements given
       in Section 3.  If not, then set s = update_seed(s) and go to Step
       1.

   9.  Set s = update_seed(s).

   10. Set k = find_integer_2(s).

   11. Determine the points Q and -Q having the smallest x-coordinate in
       E(GF(p)).  Randomly select one of them as point P.

Notes:

Rationale:
According to the first part of A.2, the routine find_integer_2()
returns an integer value (see also original step 6.).
Thus, step 2 should be deleted, and 'h' is not needed.
Note that merely renumbered steps are not taagged with
a change bar above.

Updated 2013-06-06. Thanks to Edward Huff for the correction.

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