RAR 5.0 archive format

WinRAR 5.0 introduced a new version of RAR archive format.

New features of RAR 5.0 format include:

• Compression dictionary size up to 4 GB. When compressing big files, especially in solid mode, a larger dictionary frequently allows to achieve a higher compression ratio.
• Encryption based on AES-256 algorithm, which is theoretically stronger than RAR 4.x AES-128.
• Recovery record using Reed-Solomon error correction codes with much higher resistance to multiple damages comparing to RAR 4.x recovery record.
• Faster recovery volume operations. Maximum number of RAR+REV volumes in RAR 5.0 is 65535 instead of 255.
• File times stored as Coordinated Universal Time (UTC) instead of RAR 4.x local time, making file exchange among several time zones more straightforward.
• Optional BLAKE2sp checksums for file data. Unlike CRC32 checksum, it is practically impossible for BLAKE2 to have two different files with the same checksum value. So BLAKE2 can be used for file identification purpose.
• Optional quick open information can be added to archive to provide a faster access to archive contents.
• Multithreading support in decompression algorithm. Its speed benefit is more noticeable on large files with poorly compressible data or with BLAKE2 checksums.
• Support for NTFS reparse points, symbolic links, hard links.
• Possibility to store second and following copies of identical files as references to first copy of such file.
• Complete Unicode awareness. File names and comments are stored in UTF-8 format.

WinRAR 7.0 extends this format by supporting dictionaries exceeding 4 GB. WinRAR 7.0 or newer is needed to unpack archives with such dictionaries.