diff --git a/modules/client/back/methods/tpv-transaction/confirm.js b/modules/client/back/methods/tpv-transaction/confirm.js
index 1ca2265a6..6c8ecebaf 100644
--- a/modules/client/back/methods/tpv-transaction/confirm.js
+++ b/modules/client/back/methods/tpv-transaction/confirm.js
@@ -66,17 +66,17 @@ module.exports = Self => {
         const secretKey = Buffer.from(merchant.secretKey, 'base64');
         const iv = Buffer.alloc(8, 0);
 
-        const cipher = crypto.createDecipheriv('des-ede3-cbc', secretKey, iv);
+        const cipher = crypto.createCipheriv('des-ede3-cbc', secretKey, iv);
         cipher.setAutoPadding(false);
         const orderKey = cipher.update(zeroPad(orderId, 8), 'utf8', 'base64')
-            + cipher.final();
+            + cipher.final('base64');
 
         const res = crypto.createHmac('sha256', Buffer.from(orderKey, 'base64'))
             .update(merchantParameters)
             .digest('base64');
         const base64Res = base64url.encode(res, 'base64');
 
-        // if (base64Res !== signature)
+        // if (res !== signature)
         //    throw new UserError('Invalid signature');
 
         console.debug('Payment signature:', {