# Where do you generate the salt key for vault.yml? And what is it's purpose?

**URL:** https://discourse.roots.io/t/where-do-you-generate-the-salt-key-for-vault-yml-and-what-is-its-purpose/9300
**Category:** trellis
**Created:** 2017-04-04T02:15:19Z
**Posts:** 3

## Post 1 by @s3w47m88 — 2017-04-04T02:15:20Z

In vault.yml it says

`# Documentation: [https://roots.io/trellis/docs/security/](https://roots.io/trellis/docs/security/)  
vault\_users:

- name: "{{ admin\_user }}"  
password: C9mvzdcwhmk!  
salt: “generateme”`

But it doesn’t say what URL I navigate to to generate the `salt` for that line there or in the referenced docs. Can someone tell me?

Also, in this case, I don’t understand what the `salt` us being used for.

Thank you!

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## Post 2 by @MWDelaney — 2017-04-04T03:02:08Z

The purpose is the same as any password salt, see here:

> **[Salt (cryptography)](https://en.m.wikipedia.org/wiki/Salt_(cryptography))**
>
> In cryptography, a salt is random data that is used as an additional input to a one-way function that "hashes" a password or passphrase. Salts are closely related to the concept of nonce. The primary function of salts is to defend against dictionary attacks or against its hashed equivalent, a pre-computed rainbow table attack. Salts are used to safeguard passwords in storage. Historically a password was stored in plaintext on a system, but over time additional safeguards developed to protect a us...

You can generate the salt the same place as the other salts, here:

[https://roots.io/salts.html](https://roots.io/salts.html)

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## Post 3 by @s3w47m88 — 2017-04-04T18:27:20Z

Thank you! I am new to using salts so that clarified it for me.