No secret to many people that Mac OS X is capable of performing a safe emptying of Trash (Trash) of the Finder, so that, if the user wants to get rid of his content, making it difficult to retrieve it later with some software capable of searching for deleted files, it is possible to do this with ease. Apple's desktop operating system can overwrite what's in the Trash with files without any information prior to deletion and thus (try to) protect what's inside of an attempted recovery.
For years, no one has posed any questions about this, but researchers at the University of San Diego (United States) last week presented extensive research on the topic, indicating that the integrated feature in the Finder does not work on SSDs with the same efficiency found on hard drives. . Unlike these, which permanently associate a physical location on the disk with logical blocks (magnetically overwritten with greater guarantee), solid state storage systems can reorder the way files are saved in free space via firmware, changing them from logical addresses originals.
This done by flash translation layer (FTL), which makes a magnetic memory capable of being read by the operating system as a storage disk and even benefits the consistency of what is stored on it. But when the operating system sends a command to safely delete a file, it will do so by overwriting only the logical addresses where it was originally stored, leaving an average of 60% of the information subject to being recovered after a safe emptying of the Mac OS X Trash .
The finding can be made on multiple operating systems and on drives formatted with different file systems, but it is difficult to know whether the problem is caused by the OS's file management infrastructure or by the way flash memories store information. Perhaps it is a combination of both, so that there is much to be researched by Apple on this topic to ensure greater security for user data.