Bitrot is generally from two sources: * At the sector level in physical media (tapes, disk drives, flash). The file will be largely intact, but 4- or 8-KiB chu

Bitrot is generally from two sources: * At the sector level in physical media (tapes, disk drives, flash). The file will be largely intact, but 4- or 8-KiB chunks of it will be zero'd out. * At the bit level, when copying goes wrong. Usually this is bad RAM, sometimes a bad network device, very occasionally a bad CPU. You'll see patterns like "every 64th byte has had its high bit set to 1". In both cases, the only practical option is to have multiple copies of the file, plus some checksum to decide whether a copy is "good". Files on disk can be restored from backup, bad copies over the network can be detected by software and re-transmitted.