# SHA1

The SHA (Secure Hash Algorithm) hash functions were designed by the NSA. SHA-1 is the most established of the existing SHA hash functions and it is used in a variety of security applications and protocols. However, SHA-1's collision resistance has been weakening as new attacks are discovered or improved. The message digest algorithm consists, by default, of 80 rounds. SHA1 lives in the **Hashing** category of the `fx` menu. See [SHA-1](https://datatracker.ietf.org/doc/html/rfc3174) for format details.

## Parameters

| Parameter | Type   | Required | Default | Description                                            |
| --------- | ------ | -------- | ------- | ------------------------------------------------------ |
| Input     | string | yes      | —       | Value to transform. Previous step output or a literal. |
| Rounds    | number | no       | `80`    | Numeric value. Default `80`.                           |

`Input` is the primary value (previous step output or a literal).

## Returned value

| Type     | Description                        |
| -------- | ---------------------------------- |
| `string` | Result of the SHA1 transformation. |

## Limitations

- This operation treats Input as raw bytes (binary-capable). Non-text payloads may display differently after decoding.
- Wrong key, algorithm options, or malformed input typically raises an evaluation error — fix Input or options before re-running.

## Example

<details>
<summary>Run SHA1</summary>

The SHA (Secure Hash Algorithm) hash functions were designed by the NSA. Adjust optional parameters when the defaults do not match your payload.

1. Set **Input** to the value to transform (previous step output or a literal).

2. Review **Rounds** and keep defaults unless your format requires otherwise.

3. Confirm **Output value** shows the transformed result.

</details>