Browsing history, family photos, passwords: Hardly any device knows as much about you as your smartphone.
Deleting does not mean deleting
It’s like a horrible comedy: you choose the menu “Delete”, confirm the process and the data is gone. Even if you would need them later, they are not to be found anymore. And as soon as a data rescuer comes, all the stuff is back. As if they had never been deleted, embarrassing news, unfavorable photos and all sorts of other things that you never wanted to see again come back from the digital realm of the dead.
The reason for this strange behavior of our hard drives and memory chips is their architecture. It can be thought of as a library: the data are books that are put on shelves and somewhere there is a register that says where to find which book. If you delete a file on your PC or smartphone, it will not actually be destroyed. At first only the entry in the register is deleted. For the operating system, the data is then no longer found. However, they remain on the hard disk or the memory chip until the respective area is overwritten with other data. Only then will the respective book be thrown out of the library.
Professional data rescuers do not take the detour via the registry. They search all storage elements for content. Most of what they find is just garbage. But occasionally, of course, documents, photos, music or other files. They can then be restored.
Before you sell or give away your smartphone you have to delete the data on it. Everyone knows that by now. Manufacturers offer their own option in the operating system: “Back to factory state – deletes all data on the phone” it says about Android.
The catch: That sounds safe, but it does not have to be. Because erasing does not necessarily mean that the data can not be restored.
The following steps will prevent third parties from accessing your information.
iPhone & iPad
The easiest way is to use it as a user of Apple’s smartphones and tablets. According to the manufacturer, the data is automatically encrypted on iPad and from iPhone 3GS.
5 cell phone security sins
► Switch off password protection All private data can be accessed by anyone who gets their hands on the phone.
► Install apps “somewhere on the internet”. This allows viruses and Trojans to reach the mobile phone. Only buy apps in official stores (eg iTunes).
► Skip updates Anyone who uses old versions can become the victim of known security vulnerabilities.
► Giving passwords Whoever has your AppStore password can spy on your data – or shop for your bill.
► Exchange operating system Anyone who removes the official manufacturer software (jailbreak or rooten), loses all warranty claims.
If you select under Settings → General → Reset → Delete contents & settings, the code will also be deleted for decryption with the data and overwritten by a new one.
The data can no longer be decrypted. According to Apple, data that would subsequently be read out would only be worthless garbage.
The first iPhone and the iPhone 3G, the automatic encryption is still missing. But even here the operating system overwrites the memory after clearing with zeroes.
Users of Android smartphones and tablets are not that easy for Apple users. In order to make data thieves as difficult as possible, one should first encrypt them before deleting the data.
What if I find illegal data?
Legally sensitive data on the used phone – what now? Attorney Christian Solmecke: “In criminal law there is no general duty to inform citizens. Unless it is a particularly serious offense, such as murder. “Then the new owner has to inform the police.
There is also no obligation to delete third-party data. But: “Anyone who finds child pornography content on their mobile phones should delete it immediately,” advises the lawyer. “Even the possession of such images leads to criminal liability.” No matter how one has come into possession of the images. However, anyone who does not know that these files exist, does not make a punishable offense.
Even if later information can be read from the old device, they are so useless for the buyer.
Tips for Buying a Second Mobile Phone
► Lintel marks Does the device have dents or chipped areas? The points to falls, which may have caused damage inside.
► Display Check if individual pixels are damaged. This is best recognized by displaying a white or black image on the display.
► Buttons Do all mechanical buttons and buttons work?
► Battery If possible, check the battery. If the plastic casing of the battery shows damage or deformation, keep your fingers away! The battery is damaged and could catch fire.
In general, private sellers have no guarantee or warranty.
Encrypting works on Android with on-board means – however only starting from the version 3.0. The encryption option can be found under Settings → Security → Encrypt phone. Allow some time, this process can easily take more than an hour for larger memory.
How useful are password apps?
The idea seems awesome: You put your different passwords in an app (like 1Password, iKey or LastPass) and they will take care of all registrations.
In practice this means: All important data is collected at a service. If the hacked, all accesses are threatened at once. Security experts recommend using password apps only for services in which no important private data is stored.
Incidentally, the contents of memory cards are not encrypted! Then the device can be deleted using “Settings → Backup & reset”.
Who wants to play it safe, overwrites the memory now with other harmless data, such as by the camera so long videos of your own pot plant records until the memory is full. Then the device is deleted again and the process is repeated twice.