Version 0.9.0 of Pcompress

Release Notes: This is a major release that adds support for AES encryption and Hash based Message Authentication. AES is used in CTR mode with per-chunk sequential nonce values. Unique encryption Keys are generated for every session even if the same password is used. The Scrypt mechanism from Tarsnap is utilized to generated Keys from passwords. This also includes highly-optimized SSE/AVX versions of SHA256 from Intel with runtime CPUID detection and fall-back to OpenSSL. HMAC is used to verify file and chunk headers to detect tampering.

Other releases

  •  02 Mar 2014 18:09

Release Notes: This release fixes several important bugs in the 3.0 version, making it more stable. In addition, automatic scaling of compression buffers based on compression level has been added. This improves compression ratio for the simple usage modes.

  •  12 Jan 2014 23:05

Release Notes: This is a major release featuring complete archiving capability using Libarchive and advanced data type-based compression. Appropriate algorithms for the file type are used along with various filters like PackJPG, Dispack, Delta2, etc. Files are sorted to cluster similar content and improve compression. Data split boundaries are determined from file type and rolling hash changes. Other improvements include performance tweaks, reduced memory consumption, and simplified usage.

  •  06 Sep 2013 02:40

Release Notes: This release fixes several issues, including some corner case crashes and a couple of buffer overflows. Data Deduplication can now be done using blocks as small as 2KB, providing a much higher dedupe ratio than virtually any other deduplication software. Similarity based deduplication performance has been improved. Free memory detection accuracy has also been improved.

  •  10 Aug 2013 07:24

Release Notes: This release fixes a few bugs and provides several improvements in efficiency and performance. The Similarity detection effectiveness for similarity based near-exact deduplication has been improved. At the same time memory requirements for the index has been reduced. Accuracy of data partitioning between threads has been improved. Chunking and indexing performance have been improved and the KMV Sketch computation is now more accurate. This release moves all the core functionality into a shared library in preparation for an API interface that will be introduced in future releases.

  •  28 May 2013 21:30

Release Notes: This is primarily a Bugfix release. It fixes some crashes with invalid input and build problems on Debian6 and older non-SSE4 processors. The Min-heap based Similarity matching for Delta Encoding has been improved and made faster and more accurate. Accuracy of scalable Segmented Global Deduplication has been further improved to be greater than 95%. More testcases have been added.


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