# Signing options

## Specifying a custom signature file

If you want to give the signature file a custom name or store it in a different location to the file being signed, you must specify a custom file name/path.

Here's an example:

```bash
$ kryptor -s -t "C:\Users\samuel-lucas6\Documents\file.signature" file.zip
```

## Specifying a comment

This is useful for adding instructions or metadata like an intended file name, timestamps, or version numbers.

Kryptor will verify the comment as part of the signature and display it to the user verifying the signature if verification succeeds. If you don't specify a comment, the default comment will be used.

Remember to type "speech marks" around the comment like so:

```bash
$ kryptor -s -c "Signed by Bob on the 4th of February 2022." file.zip
```

If you don't want the default comment, you can type a space as the comment:

```bash
$ kryptor -s -c " " file.zip
```

## Signing large files

If you have limited RAM, you may not be able to sign large files without prehashing. However, Kryptor automatically uses prehashing when you select a file that's equal to or greater than 1 GiB in size, so this shouldn't be a problem on most machines.

Here's an example:

```bash
$ kryptor -s -l photos.zip
```


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```
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