---
name: "singularity-sign"
section: "1"
platform: "linux"
package: "apptainer"
version: "1.5.4-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/singularity-sign"
---

# singularity-sign(1)

Add digital signature(s) to an image

## NAME

apptainer-sign - Add digital signature(s) to an image

## SYNOPSIS

**apptainer sign \[sign options...\]**

## DESCRIPTION

The sign command allows a user to add one or more digital signatures to a SIF\
   image. By default, one digital signature is added for each object group in\
   the file.

Key material can be provided via PEM-encoded file, or an entity in the PGP\
   keyring. To manage the PGP keyring, see 'apptainer help key'.

## OPTIONS

**-g**, **--group-id**=0\
 	sign objects with the specified group ID

**-h**, **--help**\[=false\]\
 	help for sign

**--key**=""\
 	path to the private key file

**-k**, **--keyidx**=0\
 	PGP private key to use (index from 'key list --secret')

**-i**, **--sif-id**=0\
 	sign object with the specified ID

## EXAMPLE

```
  Sign with a private key:
  $ apptainer sign --key private.pem container.sif
  Sign with PGP:
  $ apptainer sign container.sif
```

## SEE ALSO

**[apptainer(1)](/apptainer/1.md)**

## HISTORY

22-Sep-2026 Auto generated by spf13/cobra