diff --git a/backend/mpc-system/services/service-party-app/tss-party/main.go b/backend/mpc-system/services/service-party-app/tss-party/main.go
index dc897492..cce842a7 100644
--- a/backend/mpc-system/services/service-party-app/tss-party/main.go
+++ b/backend/mpc-system/services/service-party-app/tss-party/main.go
@@ -613,6 +613,17 @@ func executeSign(
 	// arrays to only include data for the participating signers.
 	fmt.Fprintf(os.Stderr, "[TSS-SIGN] Original keygenData has %d parties (Ks length)\n", len(keygenData.Ks))
 	fmt.Fprintf(os.Stderr, "[TSS-SIGN] Building subset for %d signing parties\n", len(sortedPartyIDs))
+
+	// Debug: print keygenData.Ks keys (first 8 chars of hex)
+	for i, k := range keygenData.Ks {
+		fmt.Fprintf(os.Stderr, "[TSS-SIGN] keygenData.Ks[%d] = %s...\n", i, hex.EncodeToString(k.Bytes())[:16])
+	}
+	// Debug: print sortedPartyIDs keys
+	for i, p := range sortedPartyIDs {
+		fmt.Fprintf(os.Stderr, "[TSS-SIGN] sortedPartyIDs[%d]: Id=%s, Moniker=%s, Key=%s\n",
+			i, p.Id[:8], p.Moniker, hex.EncodeToString(p.Key))
+	}
+
 	subsetKeygenData := keygen.BuildLocalSaveDataSubset(keygenData, sortedPartyIDs)
 	fmt.Fprintf(os.Stderr, "[TSS-SIGN] Subset keygenData has %d parties (Ks length)\n", len(subsetKeygenData.Ks))