STRONG security that fits everywhere.

P1363.1 D8

William Whyte, 2006-10-26

STRONG security that fits everywhere.

NTRU CRYPTOSYSTEMS, INC. COPYRIGHT © 2006

D7 to D8

Written comments received from David Jablon (through 1363), Mark Etzel (internal to NTRU)

Numerous typo(e)s fixed– E.g. inconsistencies in index numbering for conversion primitives

Bibliography thoroughly checked

Added conformance region recommendations to all scheme operations

One major change in terminology: PRNG to SEF– Does not result in a change in outputs but is improved description

of operation.

STRONG security that fits everywhere.

NTRU CRYPTOSYSTEMS, INC. COPYRIGHT © 2006

MGFXOR

+

e

BVGM

r

mb

m’

r*h

octL 00… OID

OS2BREP

BRE2OSPmod 2

Encryption

STRONG security that fits everywhere.

NTRU CRYPTOSYSTEMS, INC. COPYRIGHT © 2006

BVGM

Takes m, b and OID as seed

Uses this seed to generate a blinding polynomial r

Generation method: – use seed to generate stream of pseudo-random octets– convert pseudo-random octets into integers mod N

throw away duplicates or numbers that would result in bias following mod N reduction

– blinding polynomial consists of dr distinct integers

Two changes in description of BVGM:– Previously referred to first step as “PRNG”

Now refer to it as “Seed Expansion Function” (SEF) This is under discussion in X9 as well and terminology may change one more

time Final decision will be made this week

– Gave explicit means to store state to allow multiple calls after seeding This is what distinguishes SEF from MGF – MGF is only called once.