> ## Documentation Index
> Fetch the complete documentation index at: https://waasapi.uuwallet.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Frequently Asked Questions

<AccordionGroup>
  <Accordion title="1. Why use 1024-bit RSA instead of longer keys?">
    * Based on a balance between performance and security, 1024-bit RSA provides sufficient security while ensuring API response speed. Contact support for upgrades if higher security is required.
  </Accordion>

  <Accordion title="2. What to do if the public key is lost?">
    * Contact WaaS technical support to regenerate the key pair.
  </Accordion>

  <Accordion title="3. How to handle decryption failure?" defaultOpen={true}>
    * Verify response status: Check the code value. If not 0, no decryption is needed; handle business errors directly.

    * Validate data format: Ensure data is a valid Base64 string (combination of letters/numbers/+//=).

    * Verify public key consistency: Confirm the same public key is used as for request encryption (distinguish between test/production environments).

    * Check public key handling: Must first decode the Base64-encoded public key string into a byte array before using it for decryption. Do not use the Base64 string directly for decryption.
  </Accordion>

  <Accordion title="4. Why am I getting (Data must not be longer than 128 bytes;) error?" defaultOpen={true}>
    * This error occurs when attempting to decrypt data exceeding 128 bytes. To avoid this, use chunked decryption. Refer to the code examples in the RSA utility class.
  </Accordion>

  <Accordion title="5. Why am I getting (message: &#x22;Decryption failed&#x22;,code:1005, data:null) error?">
    Usually caused by:

    * 🚫 Merchant used incorrect RSA public key for encryption (inconsistent with the public key provided by WaaS).

    * 🔄 Merchant failed to properly Base64 decode the public key provided by WaaS before use (note: WaaS provides Base64-encoded public keys that require decoding before use).

    * 💾 Issues during request data serialization (e.g., contains non-UTF-8 characters or incorrect JSON format).

    * 🧩 Mismatched padding mode or algorithm during encryption (WaaS uses RSA/ECB/PKCS1Padding).
  </Accordion>
</AccordionGroup>