double mult2_precomp(int eb,big x,big y,big a2,big a6,int M,int A,int B,int C)
{
big e,c,d;
int iterations=0;
ebrick2 binst;
clock_t start;
double elapsed;
char *mem;
mem=(char *)memalloc(3);
e=mirvar_mem(mem,0);
c=mirvar_mem(mem,1);
d=mirvar_mem(mem,2);
ebrick2_init(&binst,x,y,a2,a6,M,A,B,C,WINDOW,eb);
bigbits(eb,e);
start=clock();
do {
mul2_brick(&binst,e,c,d);
iterations++;
elapsed=(clock()-start)/(double)CLOCKS_PER_SEC;
} while (elapsed<MIN_TIME || iterations<MIN_ITERS);
elapsed=1000.0*elapsed/iterations;
printf("EP - %8d iterations ",iterations);
printf(" %8.2lf ms per iteration\n",elapsed);
ebrick2_end(&binst);
memkill(mem,3);
return elapsed;
}
/*
* Class: edu_biu_scapi_primitives_dlog_miracl_MiraclDlogECF2m
* Method: computeF2mExponentiateWithPrecomputedValues
* Signature: (JJ[B)J
* This function wraps the actual computation of the exponentation with precomputed values for the requested base for Dlog groups over F2m. It gets as a parameter
* a pointer to the ebrick structure created by a previous call to initFpExponentiateWithPrecomputedValues. This implies that initFpExponentiateWithPrecomputedValues
* MUST have been called prior to this function for the same base.
*/
JNIEXPORT jlong JNICALL Java_edu_biu_scapi_primitives_dlog_miracl_MiraclDlogECF2m_computeF2mExponentiateWithPrecomputedValues
(JNIEnv * env, jobject, jlong mipp, jlong ebrick2Pointer, jbyteArray exponent){
//private native long computeF2mExponentiateWithPrecomputedValues(long mip, long ebrickPointer, byte[] exponent);
//translate parameters to miracl notation
miracl* mip = (miracl*)mipp;
big exponentB = byteArrayToMiraclBig(env, mip, exponent);
//(x,y) are the coordinates of the point which is the result of the exponentiation
big x, y;
x = mirvar(mip, 0);
y = mirvar(mip, 0);
//calculates the required exponent
mul2_brick(mip, (ebrick2*)ebrick2Pointer, exponentB, x, y);
epoint* p = new epoint();
p = epoint_init(mip);
bool valid = epoint2_set(mip, x, y, 0, p);
mirkill(x);
mirkill(y);
return (jlong)p;
}
int main()
{
int ia,ib,promptr;
epoint *PA,*PB;
big A,B,a,b,q,pa,pb,key,x,y;
ebrick2 binst;
miracl instance; /* create miracl workspace on the stack */
/* Specify base 16 here so that HEX can be read in directly without a base-change */
miracl *mip=mirsys(&instance,WORDS*HEXDIGS,16); /* size of bigs is fixed */
char mem_big[MR_BIG_RESERVE(10)]; /* we need 10 bigs... */
char mem_ecp[MR_ECP_RESERVE(2)]; /* ..and two elliptic curve points */
memset(mem_big, 0, MR_BIG_RESERVE(10)); /* clear the memory */
memset(mem_ecp, 0, MR_ECP_RESERVE(2));
A=mirvar_mem(mip, mem_big, 0); /* Initialise big numbers */
B=mirvar_mem(mip, mem_big, 1);
pa=mirvar_mem(mip, mem_big, 2);
pb=mirvar_mem(mip, mem_big, 3);
key=mirvar_mem(mip, mem_big, 4);
x=mirvar_mem(mip, mem_big, 5);
y=mirvar_mem(mip, mem_big, 6);
q=mirvar_mem(mip,mem_big,7);
a=mirvar_mem(mip, mem_big, 8);
b=mirvar_mem(mip, mem_big, 9);
PA=epoint_init_mem(mip, mem_ecp, 0); /* initialise Elliptic Curve points */
PB=epoint_init_mem(mip, mem_ecp, 1);
irand(mip, 3L); /* change parameter for different random numbers */
promptr=0;
init_big_from_rom(B,WORDS,rom,WORDS*4,&promptr); /* Read in curve parameter B from ROM */
/* don't need q or G(x,y) (we have precomputed table from it) */
init_big_from_rom(q,WORDS,rom,WORDS*4,&promptr);
init_big_from_rom(x,WORDS,rom,WORDS*4,&promptr);
init_big_from_rom(y,WORDS,rom,WORDS*4,&promptr);
convert(mip,1,A); /* set A=1 */
/* Create precomputation instance from precomputed table in ROM */
ebrick2_init(&binst,prom,A,B,CURVE_M,CURVE_A,CURVE_B,CURVE_C,WINDOW,CURVE_M);
/* offline calculations */
bigbits(mip,CURVE_M,a); /* A's random number */
ia=mul2_brick(mip,&binst,a,pa,pa); /* a*G =(pa,ya), ia is sign of ya */
bigbits(mip,CURVE_M,b); /* B's random number */
ib=mul2_brick(mip,&binst,b,pb,pb); /* b*G =(pb,yb), ib is sign of yb */
/* online calculations */
ecurve2_init(mip,CURVE_M,CURVE_A,CURVE_B,CURVE_C,A,B,FALSE,MR_PROJECTIVE);
epoint2_set(mip,pb,pb,ib,PB); /* decompress PB */
ecurve2_mult(mip,a,PB,PB);
epoint2_get(mip,PB,key,key);
/* since internal base is HEX, can use otnum instead of cotnum - avoiding a base change */
printf("Alice's Key= ");
otnum(mip,key,stdout);
epoint2_set(mip,pa,pa,ia,PB); /* decompress PA */
ecurve2_mult(mip,b,PB,PB);
epoint2_get(mip,PB,key,key);
printf("Bob's Key= ");
otnum(mip,key,stdout);
/* clear the memory */
memset(mem_big, 0, MR_BIG_RESERVE(10));
memset(mem_ecp, 0, MR_ECP_RESERVE(2));
return 0;
}
int BaseOT::Miracl_mulbrick(ebrick2* bg, big x, big y, big z)
{
return mul2_brick(bg, x, y, z);
}
int main()
{
FILE *fp;
int m,a,b,c;
big e,a2,a6,x,y,r;
epoint *g;
ebrick2 binst;
int i,d,ndig,nb,best,time,store,base;
miracl *mip=mirsys(50,0);
e=mirvar(0);
a2=mirvar(0);
a6=mirvar(0);
x=mirvar(0);
y=mirvar(0);
r=mirvar(0);
fp=fopen("common2.ecs","r");
fscanf(fp,"%d\n",&m);
mip->IOBASE=16;
cinnum(a2,fp);
cinnum(a6,fp);
cinnum(r,fp);
cinnum(x,fp);
cinnum(y,fp);
mip->IOBASE=10;
fscanf(fp,"%d\n",&a);
fscanf(fp,"%d\n",&b);
fscanf(fp,"%d\n",&c);
printf("modulus is %d bits in length\n",m);
printf("Enter size of exponent in bits = ");
scanf("%d",&nb);
getchar();
ebrick2_init(&binst,x,y,a2,a6,m,a,b,c,nb);
printf("%d big numbers have been precomputed and stored\n",binst.store);
bigdig(nb,2,e); /* random exponent */
printf("naive method\n");
ecurve2_init(m,a,b,c,a2,a6,FALSE,MR_PROJECTIVE);
g=epoint2_init();
epoint2_set(x,y,0,g);
ecurve2_mult(e,g,g);
epoint2_get(g,x,y);
cotnum(x,stdout);
cotnum(y,stdout);
zero(x); zero(y);
printf("Brickel et al method\n");
mul2_brick(&binst,e,x,y);
ebrick2_end(&binst);
cotnum(x,stdout);
cotnum(y,stdout);
return 0;
}
void Miraclmulbrick(ebrick2* bg, EC2& result, big e)
{
Big xtmp, ytmp;
mul2_brick(bg, e, xtmp.getbig(), ytmp.getbig());
MiraclInitPoint(result, xtmp, ytmp);
}