Updating and encryption Hot capuls chats cams
You can concatenate the parts to form a complete archive, or simply read them all at once by specifying a pattern in the archive name like "part??? zpaq will then search for part001.zpaq, part002.zpaq, etc.
and regard the concatenated sequence as a single archive. zpaq105 removes built in x and p preprocessors and makes them separate programs called from config files with compile time postprocessor testing.
Keys are strengthened with Scrypt(N=16384, r=8, p=1) (requiring 208M operations and 16 MB memory) to slow down brute force search for weak keys.
Encrypted archives are prefixed with a 32 byte random salt, which also provides an 8 byte IV for the first half of the 16 byte AES counter. zpaq103b adds zpaqsfx 1.03, a stub for creating self extracting archives.
This does not break forward compatibility because the decompression code is stored in the archive.
The code is written in a sandboxed, virtual machine language called ZPAQL.
Developers may be interested in the development tool and sample configuration files found on the utilities page.
zpaq is written by Matt Mahoney and released to the public domain. A zpaq archive can contain at most 4 billion files and at most 250 terabytes of data after deduplication and before compression. Do not use it to back up the operating system or any software that requires a password to install.
A password must be given every time an encrypted archive is used. zpaq104 can list and extract from self extracting archives without running them.
Deduplication requires 1 MB of memory per GB of deduplicated but uncompressed archive data to update, and 0.5 MB per GB to list or extract. From now on the specification and reference decoder are not included unless they change.
Files are added only if the date has changed since the last update. (Replaced by zpsfx in libzpaq 2.01) zpipe v1.00, a simple streaming compressor, Sept.
zpaq updates an archive by appending changes to it. zpaq106 adds "ta" to append locater tags to allow ZPAQ streams to be detected when embedded in arbitrary data.
To support remote backups without having to move huge files, zpaq can put the appended changes into a separate, numbered file that you would copy or move to remote storage.