# OP\_CHECKSIGVERIFY

<figure><img src="/files/1zAxblBe2tht88zfJTOk" alt=""><figcaption></figcaption></figure>

**OP\_CHECKSIGVERIFY** performs an ECDSA signature check consuming the top two values on the stack and allows the script to continue processing if the signature is valid.

| **Word**           | **Hex** | **Input**  | **Output**     | **Description**                                                                     |
| ------------------ | ------- | ---------- | -------------- | ----------------------------------------------------------------------------------- |
| OP\_CHECKSIGVERIFY | 0xad    | sig pubkey | Nothing / fail | Same as OP\_CHECKSIG, but runs OP\_VERIFY afterward. Fails if signature is invalid. |

**Example:**

```
<signature> <public_key> OP_CHECKSIGVERIFY
```

If the signature is invalid, the OP\_CHECKSIGVERIFY opcode causes the script to terminate and fail. This is a basic signature check script occasionally used by transactions on the network, although most wallets favor Pay To Public Key Hash (P2PKH) as the default script format.


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