diff --git a/.gitignore b/.gitignore
index edd5924..dcf3e65 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,4 @@
+bPfile
 hexcharstoraw
 *.bin
 keyhunt
diff --git a/bPfile.c b/bPfile.c
index 81a31ad..9c0117a 100644
--- a/bPfile.c
+++ b/bPfile.c
@@ -84,7 +84,7 @@ int main(int argc, char **argv)	{
 	mpz_init_set(P.x,G.x);
 	mpz_init_set(P.y,G.y);
 
-	p_file = fopen(argv[2],"a+b");
+	p_file = fopen(argv[2],"w+b");
 
 	if(p_file == NULL)	{
 		printf("Can't create file %s\n",argv[2]);
diff --git a/keyhunt.c b/keyhunt.c
index cdb0d10..4f09f55 100644
--- a/keyhunt.c
+++ b/keyhunt.c
@@ -247,9 +247,10 @@ int main(int argc, char **argv)	{
 				if(bitrange > 0 && bitrange <=256 )	{
 					/*Buscar bit_range_str_min and bit_range_str_max*/
 
-					mpz_pow_ui(MPZAUX,TWO,bitrange);
+					mpz_pow_ui(MPZAUX,TWO,bitrange-1);
 					bit_range_str_min = mpz_get_str(NULL,16,MPZAUX);
-					mpz_pow_ui(MPZAUX,TWO,bitrange+1);
+					mpz_pow_ui(MPZAUX,TWO,bitrange);
+					mpz_sub_ui(MPZAUX,MPZAUX,1);
 					bit_range_str_max = mpz_get_str(NULL,16,MPZAUX);
 					if(bit_range_str_min == NULL||bit_range_str_max == NULL)	{
 						fprintf(stderr,"[E] error malloc()\n");