Red Hat engineers have been working to more securely distribute container images. In this post we look at where we’ve come from, where we need to go, and how we hope to get there.
History
When the Docker image specification was introduced it did not have a cryptographic verification model. The most significant reason (for not having one) was the lack of a reliable checksum hash of image content. Two otherwise identical images could have different checksum values. Without a consistent tarsum mechanism, cryptographic verification would be very challenging. With Docker version 1.10, checksums are more consistent and could be used as a stable reference for cryptographic verification. The version 2 image format provides an image manifest digest hash value that is useful for this.
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