# make_auth_message · FT4 Rell API · Chromia Docs (concept)

> function make_ auth_ message(message: text): text A utility function that adds a header and a footer to every auth message. The header contains the blockch

Source: https://docs.chromia.com/pages/ft4-rell/-f-t4-library/lib.ft4.utils/make_auth_message/

FUNCTION

# make\_auth\_message

```signature
function make_auth_message(message: text): text
```

[Source](https://gitlab.com/chromaway/ft4-lib/-/blob/development/rell/src/lib/ft4/utils/utils.rell#lines-38)

A utility function that adds a header and a footer to every auth message.

The header contains the blockchain RID to avoid the same signature to be maliciously used
on other chains in a cross-chain replay attack.

The footer contains a nonce to avoid the same signature to be maliciously used on this same
chain in a classic replay attack.

**Parameters**

* **message** — the body of the message

[View this page on docs.chromia.com](https://docs.chromia.com/pages/ft4-rell/-f-t4%20-library/lib.ft4.utils/make_auth_message.html)Generated API reference, mirrored from the live docs