# RFC Errata

### RFC 5931, "Extensible Authentication Protocol (EAP) Authentication Using Only a Password", August 2010

Source of RFC: IETF - NON WORKING GROUPArea Assignment: sec

See Also: RFC 5931w/ inline errata

Errata ID: 3109

**Status: Verified
Type: Technical
Publication Format(s) : TEXT**

Reported By: Dan Harkins

Date Reported: 2012-02-06

Verifier Name: Sean Turner

Date Verified: 2012-05-04

Section 2.2.2 says:

An integer scalar, x, acts on an ECC group element, Y, via repetitive addition (Y is added to itself x times), also called point multiplication -- x * Y. The inverse function for an ECC group is defined such that the sum of an element and its inverse is the "point at infinity" (the identity for elliptic curve point addition). In other words, Q + inv(Q) = "O"

It should say:

An integer scalar, x, acts on an ECC group element, Y, via repetitive addition (Y is added to itself x times), also called point multiplication -- x * Y. ECC groups require the use of a mapping function, F(), which returns the x-coordinate of a point on the elliptic curve. In other words, if point Y has coordinates Y.x and Y.y, then, Y.x = F(Y) The inverse function for an ECC group is defined such that the sum of an element and its inverse is the "point at infinity" (the identity for elliptic curve point addition). In other words, Q + inv(Q) = "O"

Notes:

Section 2.8.4.1 mentions function F() as defined in 2.2.2 but there is no

function F() in 2.2.2.