# digest.sha512

The `digest.sha512` function returns the SHA-512 digest of a string as lowercase hexadecimal. It takes
the same argument as [`digest.sha256`](/functions/automation/digest.sha256) and returns a 128-character
string. Use it when a registry or checksum file expects SHA-512.

## Usage

```python
digest.sha512(data)
```

## Arguments

- **`data`**
  Required. The string to hash, as bytes. File contents from 
  `fs.read_file`
   hash exactly as stored.

## Returns

The digest as a 128-character lowercase hexadecimal string.

## Example

### Verify a download against a SHA-512 checksum file

```python
expected = fs.read_file("release.tar.gz.sha512").split()[0]
actual = digest.sha512(fs.read_file("release.tar.gz"))
if actual != expected:
    fail("checksum mismatch for release.tar.gz")
```

## Errors

- A missing argument, or an argument that is not a string, fails with an argument error.

## Related

- [`digest.sha256`](/functions/automation/digest.sha256) is the usual choice for fingerprints and cache keys.
- [Atmos Automation Language](/scripting/language) and the [script step](/steps/type/script)