# POST /Indoor/api/decryptDataBlock

**Resource:** [PIN and card security](../resources/PIN-and-card-security.md)
**Service that decrypts the data block**
**Operation ID:** `decryptDataBlock`

Decrypts an encrypted data block using KMT service. Validates that EncryptDataBlock is not null or empty, retrieves encryption parameters from cache, calls DecryptDataBlock on KMT proxy with KeyId, IV, and CBC mode, and returns the clear data block.

## Request Body

Decrypt Data Block Request

**Required:** Yes

**Content Types:** `application/json`

**Schema:** [DecryptDataBlockRequest](../schemas/Decrypt/DecryptDataBlockRequest.md)

## Responses

| Status | Description |
|--------|-------------|
| 200 | Success |
| 400 | (reference) |
| 404 | (reference) |
| 500 | (reference) |

**Success Response Schema:**

[DecryptDataBlockResponse](../schemas/Decrypt/DecryptDataBlockResponse.md)

