The deduplication mechanism in HPE StoreOnce Catalyst relies on cryptographic and mathematical hash comparisons, not on encryption algorithms. During the ingestion pipeline, data streams are fragmented into variable-length chunks, and each chunk is evaluated using secure cryptographic hashing algorithms (such as SHA) to generate a unique digital fingerprint.

The deduplication engine compares these calculated hashes against an existing index of previously stored block fingerprints. If a hash matches an entry in the catalog, the chunk is identified as duplicate data and discarded, and a lightweight pointer referencing the existing data is recorded instead. Only non-matching, unique chunks are committed to storage. Data encryption is a separate security process applied to protect data confidentiality at rest or in transit, and it plays no functional role in determining chunk uniqueness.