fix preparation for M+1st price auctions

1 files changed, 2 insertions, 2 deletions

diff --git a/crypto.c b/crypto.c
index 1d0dae3..3e4991d 100644
--- a/crypto.c
+++ b/crypto.c
@@ -741,7 +741,7 @@ smc_encrypt_bid (struct BRANDT_Auction *ad, size_t *buflen)
 		gcry_mpi_addm (r_sum, r_sum, r_part, ec_n);
 
 		/* prepare sum for additional  M+1st price auction proof (see below) */
-		if (0 < ad->m && j >= ad->i && 0 == (j - ad->i) % ad->n)
+		if (0 < ad->m && 1 == (ad->k - j - ad->i) % ad->n)
 			gcry_mpi_addm (r_sum2, r_sum2, r_part, ec_n);
 
 		cur += 2 * sizeof (struct ec_mpi) + sizeof (struct proof_0og);
@@ -809,7 +809,7 @@ smc_recv_encrypted_bid (struct BRANDT_Auction *ad,
 
 		/* precalculate ciphertext sums for second 2dle proof needed in M+1st
 		 * price auctions */
-		if (0 < ad->m && j >= ad->i && 0 == (j - ad->i) % ad->n)
+		if (0 < ad->m && 1 == (ad->k - j - sender) % ad->n)
 		{
 			gcry_mpi_ec_add (alpha_sum2, alpha_sum2, ct[0][j], ec_ctx);
 			gcry_mpi_ec_add (beta_sum2, beta_sum2, ct[1][j], ec_ctx);