---

id: ff title: FF sidebar_label: FF

FF

Kind: global class
this: {FF}

• FF
  • new FF()
  • instance
    • .set(m)
    • .copy(b)
    • .rcopy(b)
    • .dsucopy()
    • .dscopy()
    • .sducopy()
    • .iszilch()
    • .shrw()
    • .shlw()
    • .parity()
    • .radd()
    • .rinc()
    • .rsub()
    • .rdec()
    • .add()
    • .sub()
    • .revsub()
    • .inc()
    • .rnorm()
    • .shl()
    • .shr()
    • .toString()
    • .toBytes()
    • .karmul()
    • .lmul()
    • .mod()
    • .reduce(N, ND) ⇒
    • .dmod(b) ⇒
    • .invmodp()
    • .nres()
    • .invmod2m()
    • .randomnum()
    • .modmul()
    • .modsqr()
    • .skpow(e, p)
    • .skspow(e, p)
    • .power(e, p)
    • .pow(e, p)
    • .pow2(e, y, f, p)
    • .cfactor(s) ⇒
  • static
    • .comp(a, b) ⇒
    • .cswap()
    • .mul()
    • .sqr()
    • .prime(p, rmg)

new FF()

Creates an instance of FF.

fF.set(m)

set to integer

Kind: instance method of FF
this: {FF}

Param	Description
m	Integer value to be set to

fF.copy(b)

copy from FF b

Kind: instance method of FF
this: {FF}

Param	Description
b	FF element to copy from

fF.rcopy(b)

copy from FF b

Kind: instance method of FF
this: {FF}

Param	Description
b	FF element to copy from

fF.dsucopy()

x=y<<n

Kind: instance method of FF
this: {FF}

fF.dscopy()

x=y

Kind: instance method of FF
this: {FF}

fF.sducopy()

x=y>>n

Kind: instance method of FF
this: {FF}

fF.iszilch()

test equals 0

Kind: instance method of FF
this: {FF}

fF.shrw()

shift right by BIGBITS-bit words

Kind: instance method of FF
this: {FF}

fF.shlw()

shift left by BIGBITS-bit words

Kind: instance method of FF
this: {FF}

fF.parity()

extract last bit

Kind: instance method of FF
this: {FF}

fF.radd()

recursive add

Kind: instance method of FF
this: {FF}

fF.rinc()

recursive inc

Kind: instance method of FF
this: {FF}

fF.rsub()

recursive sub

Kind: instance method of FF
this: {FF}

fF.rdec()

recursive dec

Kind: instance method of FF
this: {FF}

fF.add()

simple add

Kind: instance method of FF
this: {FF}

fF.sub()

simple sub

Kind: instance method of FF
this: {FF}

fF.revsub()

reverse sub

Kind: instance method of FF
this: {FF}

fF.inc()

increment/decrement by a small integer

Kind: instance method of FF
this: {FF}

fF.rnorm()

normalise - but hold any overflow in top part unless n<0

Kind: instance method of FF
this: {FF}

fF.shl()

shift left by one bit

Kind: instance method of FF
this: {FF}

fF.shr()

shift right by one bit

Kind: instance method of FF
this: {FF}

fF.toString()

Convert to Hex String

Kind: instance method of FF
this: {FF}

fF.toBytes()

Convert FFs to/from byte arrays

Kind: instance method of FF
this: {FF}

fF.karmul()

z=x*y, t is workspace

Kind: instance method of FF
this: {FF}

fF.lmul()

return low part of product this*y

Kind: instance method of FF
this: {FF}

fF.mod()

Set b=b mod c

Kind: instance method of FF
this: {FF}

fF.reduce(N, ND) ⇒

return this mod modulus

Kind: instance method of FF
Returns: this mod N
this: {FF}

Param	Description
N	Mmodulus
ND	Montgomery Constant

fF.dmod(b) ⇒

Reduces a double-length FF with respect to a given modulus

Kind: instance method of FF
Returns: this mod N
this: {FF}

Param	Description
b	Mmodulus

fF.invmodp()

Set return=1/this mod p. Binary method - a<p on entry

Kind: instance method of FF
this: {FF}

fF.nres()

nresidue mod m

Kind: instance method of FF
this: {FF}

fF.invmod2m()

U=1/a mod 2^m - Arazi & Qi

Kind: instance method of FF
this: {FF}

fF.randomnum()

generate random x

Kind: instance method of FF
this: {FF}

fF.modmul()

this*=y mod p

Kind: instance method of FF
this: {FF}

fF.modsqr()

this*=y mod p

Kind: instance method of FF
this: {FF}

fF.skpow(e, p)

this=this^e mod p using side-channel resistant Montgomery Ladder, for large e

Kind: instance method of FF
this: {FF}

Param	Description
e	exponent
p	modulus

fF.skspow(e, p)

this=this^e mod p using side-channel resistant Montgomery Ladder, for short e

Kind: instance method of FF
this: {FF}

Param	Description
e	exponent
p	modulus

fF.power(e, p)

raise to an integer power - right-to-left method

Kind: instance method of FF
this: {FF}

Param	Description
e	exponent
p	modulus

fF.pow(e, p)

this=this^e mod p, faster but not side channel resistant

Kind: instance method of FF
this: {FF}

Param	Description
e	exponent
p	modulus

fF.pow2(e, y, f, p)

double exponentiation r=x^e.y^f mod p

Kind: instance method of FF
this: {FF}

Param	Description
e	exponent
y	FF instance
f	exponent
p	modulus

fF.cfactor(s) ⇒

Test if an FF has factor in common with integer s

Kind: instance method of FF
Returns: true or false
this: {FF}

Param	Description
s	integerexponent

FF.comp(a, b) ⇒

compare a and b - must be normalised, and of same length

Kind: static method of FF
Returns: zero of error codetrue or false
this: {FF}

Param	Description
a	FF number
b	FF number

FF.cswap()

in-place swapping using xor - side channel resistant - lengths must be the same

Kind: static method of FF
this: {FF}

FF.mul()

z=x*y. Assumes x and y are of same length.

Kind: static method of FF
this: {FF}

FF.sqr()

z=x^2

Kind: static method of FF
this: {FF}

FF.prime(p, rmg)

Miller-Rabin test for primality.

Kind: static method of FF
this: {FF}

Param	Description
p	FF instance to be tested
rmg	an instance of a Cryptographically Secure Random Number Generator