> For the complete documentation index, see [llms.txt](https://docs.mosip.io/compliance-tool-kit/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.mosip.io/compliance-tool-kit/developer-guides/hash-generation.md). # Hash Generation Generation and Verification of Hash for SBI and SDK: * In order to maintain the integrity of the SBI/SDK software solution, a cryptographic hash function has been implemented. This function has been thoroughly tested by CTK and found to be compliant with the MOSIP specification. * It is a requirement for partners to calculate the HASH of the software solution using the SHA256 hash function, regardless of the technology environment in which the devices will be utilized. * Furthermore, the calculated HASH of the solution should remain unchanged, allowing countries or relying parties to recalculate the HASH and validate the software's integrity prior to deployment. * In the event that the software undergoes any changes, the partner must calculate a new HASH and retest the solution using CTK in order to maintain their compliance status. ## Hash Generation for Android App: * The Blake2b or SHA256 algorithms can be utilized to calculate the hash value of an APK file. * Blake2b produces digests with a byte size ranging from 1 to 64 and is specifically designed for 64-bit systems. * SHA256 is an unkeyed cryptographic hashing method that generates a 256-bit hash outcome from an input of variable length. * The hash value of an APK file can be determined using Windows PowerShell, which defaults to employing the SHA256 algorithm. * The hash value will be altered in the event of any modifications made to the APK file. Conversely, the hash value will remain constant if no changes are made.