# HEADER_ALG

> `const` **HEADER\_ALG**: `1` = `1`

Defined in: [packages/filecoin-encryption-envelope/src/cose/constants.ts:19](https://github.com/FilOzone/synapse-sdk/blob/bc8a4b093324ccef9b407251fcf4e91823c6f599/packages/filecoin-encryption-envelope/src/cose/constants.ts#L19)

`alg`, RFC 9052 §3.1. Selects the encryption scheme, see the ALG_* constants.