# 3‑D Secure authentication on merchant side {#en_gate_merchant_3ds}

An article about an additional option of authenticating customers with the use of the 3‑D Secure protocol for processing card payments via Gate, performed through third-party solutions and initiated by the merchant.

## General information {#section_i3t_kkq_qmb .section}

Customer 3‑D Secure authentication can be performed either on the Ecommpay payment platform side or on the merchant side. If authentication is performed on the merchant's side, the authentication result must be sent to the payment platform in order to make a payment. Repeated authentication on the payment platform side will not occur.

To enable the capability, contact technical support \([support@ecommpay.com](mailto:support@ecommpay.com)\).

## Sending the 3‑D Secure authentication result {#section_vfr_mkq_qmb .section}

Information about the 3‑D Secure authentication result is passed in the `authentication_data` object in a request for performing a one-time purchase, including purchases that use a token or saved card data, or a request for card verification. Data is passed in the following parameters:

|Parameter|Type|Mandatory|Description|
|---------|----|---------|-----------|
|`cavv`|string|Mandatory if `authentication_status=Y or A`|Cardholder authentication verification value \(base64 encoded, 20 bytes in a decoded form\)|
|`ds_operation_id`|string|Mandatory if `threeds_version=3ds_2`|The unique operation identifier assigned by the Directory Servers|
|`eci`|string|Mandatory if `authentication_status=Y or A`|The electronic commerce indicator, for more information, see the section [Electronic Commerce Indicators](en_ECI_codes.md)|
|`threeds_version`|string|Optional|Indicator of the 3‑D Secure authentication:-   `3ds_2`
-   `non_3ds`

|
|`threeds_full_version`|string|Optional|The version of the 3‑D Secure protocol, for example 2.3.1|
|`xid`|string|Mandatory|Transaction identifier resulting from authentication processing \(base64 encoded, 20 bytes in a decoded form\)|
|`authentication_status`|string|Mandatory, except if `enrollement_status=N or U`|Cardholder authentication status. Possible values are:

 -   `Y`—the cardholder was successfully authenticated by their card issuer
-   `A`—the cardholder authentication was attempted
-   `U`—the card issuer was unavailable during the authentication attempt

|
|`authentication_status_reason_code`|string|Optional|Code of the authentication status reason|
|`authentication_flow`|string|Optional|Scenario of 3‑D Secure authentication-   `Frictionless`,
-   `Challenge`

|

```
{
   "general":{
      "project_id":200,
      "payment_id":"id_15514400636",
      "signature":"PJkV8ej\/UG0Di8hTng6JvC7vQsaC6tajQ...=="
   },
   "card":{
      "pan":"some_string",
      "year":2025,
      "month":12,
      "card_holder":"JOHN JOHNSON",
      "cvv":"some_string"
   },
   "customer":{
      "id":"123",
      "ip_address":"217.1.1.0"
   },
   "payment":{
      "amount":1000,
      "currency":"EUR"
   },
   "authentication_data":{
      "cavv":"kEMQyiH/ASySYhP1hAErbWFO+mih",
      "ds_operation_id":"f780a79f-a5e1-44d8-bfa3-5f89432fdb79",
      "eci":"06",
      "threeds_version":"3ds_2",
      "xid":"MDAwMDAwNzYxODEwMDAwMDE3MDE=",
      "authentication_status":"A",
      "authentication_flow":"Frictionless",
      "threeds_full_version":"2.3.1",
      "authentication_status_reason_code":"01"
   }
}
```

## Related topics {#section_xsx_3jl_ggb .section}

The following topics can be useful when implementing payments through Gate:

-   [Interaction concepts](en_gate_interaction_organisation.md#)
-   [Signature generation and verification](en_platform_signature.md#)
-   [Payment processing](en_platform_payment_model.md)
-   [Handling operation processing information](en_platform_payment_info_codes.md)
-   [3‑D Secure authentication](en_gate_payment_3ds.md#)

**Parent topic:**[Auxiliary procedures](en_gate_procedures.md)