File Hashing & Verification
Inline and post-copy hash verification with 8 algorithms, plus a standalone file hasher tool supporting 25 algorithms for auditing and comparison.
Copy Verification
The copy engine supports 8 hash algorithms for inline and post-copy verification:
| Algorithm | Notes |
|---|---|
| BLAKE3 | Modern, fastest cryptographic hash (recommended) |
| CRC32 | Fast non-cryptographic checksum |
| CRC32C | Castagnoli variant, hardware-accelerated on modern CPUs |
| MD5 | 128-bit legacy hash |
| SHA-1 | 160-bit legacy hash |
| SHA-256 | 256-bit NIST standard |
| SHA-384 | 384-bit SHA variant |
| SHA-512 | 512-bit SHA variant |
Multiple algorithms can run simultaneously for additional confidence.
Verification Modes
Two modes are available and can be combined:
- Hash During Copy (inline) — data is hashed as it flows through the copy pipeline, adding zero extra I/O. Source and destination hashes are computed simultaneously and compared at the end of the copy.
- Verify After Copy (post-copy) — a separate sequential read pass re-hashes the destination file and compares it to the source hash. Slower but guaranteed sequential reads.
Note: for files over 1 GB, we recommend using Verify After Copy alone. The inline mode's overlapped I/O can produce out-of-order hash data on very large files.
File Hasher Tool
The standalone File Hasher tool (under Advanced Tools) supports 25 hash algorithms for file hashing, comparison, and auditing:
CRC32, CRC32C, MD4, MD5, SHA-0, SHA-1, SHA-224, SHA-256, SHA-384, SHA-512, xxHash32, xxHash64, MurmurHash3-32, MurmurHash3-128, FNV-1a-32, FNV-1a-64, Grindahl-256, Grindahl-512, BLAKE3, HAS-160, RIPEMD, RIPEMD-128, RIPEMD-256, RIPEMD-320, WhirlPool
Features include single-folder hashing, side-by-side folder comparison, multi-algorithm simultaneous hashing, CSV export, pause/resume, and parallel processing across multiple threads.