---
page_title: Card encryption - Standalone Tokenization APIs
product: API Reference
page_source: https://juspay.io/in/docs/api-reference/docs/tokenization-apis/card-encryption-standalone-tokenization-apis
llms_txt: https://juspay.io/in/docs/llms.txt
product_llms_txt: https://juspay.io/in/docs/api-reference/llms.txt
---


# Card Data Encryption - Standalone Tokenization APIs



This script is used to **encrypt card details** and **decrypt the API response using JWE encryption**  for standalone API testing. It is primarily used when calling APIs that require encrypted card data, such as[](https://juspay.io/in/docs/api-reference/docs/tokenization-apis/generate-network-token)**[Generate Token](https://juspay.io/in/docs/api-reference/docs/tokenization-apis/generate-network-token)** [](https://juspay.io/in/docs/api-reference/docs/tokenization-apis/generate-network-token)and **[Get Alt ID](https://juspay.io/in/docs/api-reference/docs/tokenization-apis/fetch-alt-id-and-cryptogram-api)**  APIs.


## **Step 1: Card Data Preparation** 



**Prepare your card payload in JSON format:** 


#### Shell Code Snippet:

```shell
{

  "cardNumber": "5555555555554444",

  "expMonth": "11",

  "expYear": "2031",

  "cardSecurityCode": "123"

}
```



## **Step 2: Encrypt Card Data** 



**Use the public key to encrypt the above payload. Here’s a simple Python script:** JWE Encryption / Decryption Script – Setup & Run GuideThis script encrypts and decrypts card payloads using **JWE (JSON Web Encryption)**  with the **RSA-OAEP-256**  algorithm and **A128GCM**  encryption.It uses the Python library **jwcrypto** .


### Prerequisites:



Make sure the following are installed.

**1.Python** 

Python **3.8+ recommended** 

Check version:


#### Python Code Snippet:

```python
python3 --version
```


**2.Install Required Library** 

Install **jwcrypto** :


#### python Code Snippet:

```python
pip3 install jwcrypto
```


**3.Required Files** 

You need the following keys:

**FilePurpose:** `Public Key (.pem):Used for encryption``Private Key (.pem)Used for decryption`**4. Update Key Paths in Script** 

Update the **Juspay** **public key path**  inside the encrypt function.

Replace:

**recipient=loadPem** ('publickeyfilelocation')

with:

**recipient=loadPem** ('/path/to/publicKey.pem')


---


Update the **private key path**  inside the decrypt function.

Replace:

**loadPem** ('privateKeylocation')

with:

**loadPem** ('/path/to/privateKey.pem')


## **Step 3:** Script:




#### python Code Snippet:

```python
from jwcrypto import jwk, jwe
import json

def encrypt(payload):
    payload = json.dumps(payload)
    protected_header = {
        "alg": "RSA-OAEP-256",  # Encryption algorithm
        "enc": "A128GCM",       # Content encryption algorithm
        "kid": "2218168c-ee6b-49d7-a851-8b94e7d0068d"  
    }
    
   
    jwetoken = jwe.JWE(payload.encode('utf-8'),
                       recipient=loadPem('publickeyfilelocation'),# Add juspay public key
                       protected=protected_header)
 
    encryptedPayload = jwetoken.serialize(compact=True)
    return json.dumps({"encData": encryptedPayload})

def loadPem(filePath):
    # Load a PEM file from a given path
    with open(filePath, "rb") as pemfile:
        return jwk.JWK.from_pem(pemfile.read())

def decrypt(encPayload):
   
    if type(encPayload) is str:
        payload = json.loads(encPayload)
        
        
        if payload.get('encData', False):
            jwetoken = jwe.JWE()
            jwetoken.deserialize(payload["encData"], 
            key=loadPem('privatekeyfilelocation'))# Add Juspay merchant's private key
            
           
            return json.dumps(json.loads(jwetoken.payload))
    
    return encPayload


if __name__ == "__main__":
 


# Encrypt the payload
  encrypted_data = encrypt('{"cardNumber":"5186001700008785","expMonth": "07","expYear": "2027","cardSecurityCode":"123"}')
  print("Encrypted data:", encrypted_data)

# Decrypted_data the payload
decrypted_data = decrypt('{"encData": "eyJhbGciELsnfczgqhZIOM4sz-avv932ZNiKm-G4GEOE_bF_b6QSqiDRn5JzppqNC3kQCRaEQgzZMnir17TK2Z386aF82rfKVaADJl-xGrsRC9dJAAsKomrdwOykkNwonaag9isL8P5EYVhsqY9jCpWzqv4WgwZ5MaMqRvXLj6ju02_m4-n46vpPf01fYYiHTzkb6v9N_W2bTA0-g0eSUi1AUxhhxM9oGwvg5O-tzDB8Z0EW3NQp7Ao-"}')
print("Decrypted data:", decrypted_data)

```



## Download Juspay Public Key



Use the following public keys to **encrypt card details before sending requests to Juspay APIs** .


### Sandbox



Download the **[Juspay Sandbox Public Key](https://dth95m2xtyv8v.cloudfront.net/tesseract/assets/api-reference/sandbox-public-key-kz3yl.pem)**  for testing environments.


### Production



Download the **[Juspay Production Public Key](https://dth95m2xtyv8v.cloudfront.net/tesseract/assets/api-reference/juspay_public_prod-4V3nX.pem)**  for production environments.

> **Note**
> Please download the **private key**  from the **respective merchant’s dashboard** . The private key is required to **decrypt the encrypted API response**  generated by Juspay.
> 
> ![Image](https://dth95m2xtyv8v.cloudfront.net/tesseract/assets/api-reference/Screenshot%202026-03-11%20at%205.29.46%E2%80%AFPM.png)
> *Merchant’s Dashboard*
> 
> 
> 
> You can download the key from the following location in the merchant dashboard:
> 
> **Path:** `Settings → Security → RSA Keys`



---

## See Also

- [Glossary](https://juspay.io/in/docs/api-reference/docs/direct-otp/glossary)
- [Generate Network Token](https://juspay.io/in/docs/api-reference/docs/tokenization-apis/generate-network-token)