I'm not sure anyone is going to invest a year's worth of computation with 100 GPUs to generate a colliding SHA1 sum for an installer image which normally has a three-month lifespan, especially when there's a GPG signature too.
That said, it takes zero net effort to switch from sha1 to sha256, or minimal extra to provide each sha1, sha256, and sha512, so we should just do it.
@Maintainers Can you easily generate a number of different checksums for the installer images?
I've been sharing Manjaro with friends and teammates and I share it via the main website and downloads page. I've had 3 people message me while checking out the distro and ask why the downloads page provides SHA1 rather than SHA256.
I personally understand the context of how difficult and complex an attack from this vector would be, but my hope is that it will be found to be so simple to change that it won't be a problem. In that way we can take care of the actual technical security issue that underlies, but also improve perception of the distro a small bit based on my own experiences sharing it.
Back in the days our download provider offered sha1sum by default when hovering over. We already recommend to check via the signature file rather checksums. We will see if it makes sense to display other sums instead of sha1.
I understand and appreciate the thoughts brought up in this post Jonathan, and I get where you're coming from. My thoughts still lean towards it being better to display the stronger hash on that first download page people hit based on the assertions in this thread so far that it should be simple to change. I'm curious to hear your continued thoughts on this.