![]() I was just reading this thread as I was looking for an answer to a problem I had today with a newly installed v5.0 CCleaner.I had to install again as there was a problem with my pc losing part of a file.When I uninstalled, I thought I'd load the new version. Hi, I'm pretty new to this forum, although I have popped in from time to time. Otherwise I have utilities that will do a byte by byte comparison - It is a capability I almost never use - life is too short. When I want to "know for sure" whether two files are the same then I use "HashMyFiles" from Nirsoft, and I am happy to live with the 1 in millions of possibilities that the same bit restricted hash output could be produced by files with different content, The only difference I can see is in the amount of the probability of error. SHA-512 is overwhelmed by a 64 kB file just as much as CCR32 is just overwhelmed by a 4 kB file. I do not understand how you expect perfect distinction via "proper hashing algorithm" between files that are likely be hundreds of times larger than 64 bytes.ĬCR32 has a 32 bit output value which can distinguish between any two files that are up to 4 bytes in size SHA-512 has an output value of 512 bits that can distinguish between any two files that are up to 64 bytes in size MD5 has an output value of 128 bits that can distinguish between any two files that are up to 16 bytes in size Please explain why you would believe that. That is a risk I am happy to take - I do not even have 4 billion files with different namesĪgain, it's not just as simple as the theoretical mathematics. Then on average one file may have been deleted even though the content was different. To finish off by computing checksums to ensure the contents also match.Ī CRC32 error rate of one in 4,294,967,296 means that after deleting 4,294,967,296 "duplicate" files, It can only be sensible to look for matching file names and sizes,Īnd then as suggested in this topic title, If you really want to avoid malicious 'cleverness' you need SHA-256 or better,Īnd it would be infinitely preferable to validate a download BEFORE it ever gets moved into your system for use before CCleaner ever gets around to accessing it. I totally disagree with recommending MD5 for protection against malicious 'cleverness', because some years ago it was being cracked, see for example. I totally disagree with your conclusions as applied to this particular application. I think having a (reliable) duplicate file finder built right into CCleaner is an excellent thing, but at the moment it just isn't. I'm sorry if I'm sounding overly critical/negative. You need to use a proper hashing algorithm, such as MDx or SHA-x. It's not an issue of mathematics, it's an issue of maliciousness (and fundamentally design). Not even CRC32, this is simply not suitable. ![]() It's just these sorts of suspicious files you might want to verify. I've seen on numerous occasions, through either malicious 'cleverness' or simply quirks of design, DISTINCT files that share the same CRC32 but clearly not the same MD5/SHA-1. To have an even half way proper duplicate file finder, the mechanism for identifying such files MUST be some sort of hashing algorithm *as a CRC32, this is simply not suitable. This duplicate photo finder for macOS scans for duplicate photos from a selected drive or folder on your Mac.I completely agree with Keatah and 4NTFan.Īs a long time fan of CCleaner I was excited to see this new feature added, but in its current implementation it's beyond useless. It helps you effectively manage and organize the photo collection on your Mac by finding duplicate photos and removing them safely in a few clicks. Photos Duplicate Cleaner a free-to-use duplicate photo finder Mac users can install and use. Now, enhancing the space and performance of your Mac is made easier through iMyMac’s tools. ![]() It only takes a few clicks to go through the entire process. Fortunately, for MAC users, iMyMac-PowerMyMac’s Duplicate Finder can be used to find duplicate or similar images on your Mac and free up your much-needed storage space.
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