Hash Algorithms Supported by 7-Zip

While SHA-256 is the standard choice for verifying file integrity, 7-Zip includes native support for several other checksum and cryptographic hashing algorithms. This guide outlines the alternative hash algorithms available in 7-Zip, their intended uses, and how to generate them using both the graphical interface and the command line.

Alternative Hash Algorithms in 7-Zip

In addition to SHA-256, 7-Zip can calculate the following hash values:

  • CRC-32: A 32-bit Cyclic Redundancy Check used primarily to detect accidental changes or corruption in data transfer and storage. It is extremely fast to compute, though it is not cryptographically secure and should not be used to detect intentional tampering.
  • CRC-64: A 64-bit version of the Cyclic Redundancy Check. Like CRC-32, it is designed for error-checking rather than security, but it provides a lower probability of accidental collision due to its larger output size.
  • SHA-1: A 160-bit cryptographic hash function developed by the NSA. Although it has been deprecated for high-security applications due to known theoretical collision vulnerabilities, it remains widely used for backward compatibility and basic file integrity checks.
  • BLAKE2sp: A parallelized implementation of the BLAKE2s cryptographic hash function optimized for multi-core 64-bit processors. It provides security comparable to standard SHA-2 family hashes while offering significantly faster calculation speeds across large files.

How to Calculate Hashes in 7-Zip

Using the Windows Context Menu

  1. Right-click the file or folder you want to verify.
  2. Hover over the CRC SHA option in the context menu.
  3. Select the specific algorithm you want to compute (such as CRC-32, CRC-64, SHA-1, or BLAKE2sp).
  4. Select the * (asterisk) option if you want 7-Zip to calculate all supported hashes simultaneously.

Using the Command Line

You can also calculate these hashes using the 7-Zip command-line utility (7z.exe) using the h command:

7z h -scrc<Algorithm> filename.ext

Replace <Algorithm> with CRC32, CRC64, SHA1, or BLAKE2sp. Omitting the algorithm flag will default to calculating the CRC-32 checksum.