Android 5.0 or will cancel the encryption Google eventually give up full encryption

MWC2015 ushered in a large wave of equipment running Android 5.0, Samsung's most beautiful Galaxy S6 and S6 Edge, "successive" HTC One M9, and Moto E (2015) and so on. Regarding Android 5.0 itself, what many people don't realize is that Google has quietly relaxed the restrictions of full-disk encryption, which are not enabled by default in these devices.


At the beginning of the release of Nexus 6, Ai Faner reported that Android 5.0 defaults to the "full encryption" feature, which can seriously slow down the system's read and write performance:
According to AnandTech's test results, the Nexus 6 with Android 5.0 system has a random read performance drop of 62.9%, random write performance drop of 50.5%, and an orderly read performance drop is amazing. 80.7%.

Full disk encryption, Full Disk Encryption (FDE). When FDE is turned on, all data written to the hard disk needs to be encrypted first. All read data needs to be decrypted first. This is an important improvement of Android 5.0 over previous products, which greatly enhances the security of Android devices, and Google has emphasized the positive significance of this improvement on several occasions.

The frustration is that, under the current hardware conditions of Android, the eMMC flash memory on most models does not have its own encryption standard, and the SoC on the phone does not have a dedicated module to handle the data encryption/decryption function. . These are the direct result of Android 5.0 in the open disk encryption, the performance of the machine will be a substantial decline.

Security, or performance, may not be a difficult trade-off for many people, because at present, only two machines are enabled by default for full-disk encryption - the Nexus 6 and the Nexus 9, even the original Nexus. The series model will not open this function after upgrading Android 5.0.

Now, Google returned the option to the OEM, "recommended" to start this full-disk encryption, but it seems that there is not much mobile phone manufacturer response. However, we hope that Google’s efforts in system security will not be disastrous. The biggest reason, as mentioned above, is that the hardware design of mobile phones has not kept pace with the rapid change of mobile operating systems. More reliable solutions include faster flash chips, faster file systems such as F2FS, and optimized SoC data encryption and decryption performance.

Different from Google’s aggressive promotion of "full-disk encryption" when it released Android 5.0, Google changed the Android system compatibility document a month ago, but the end-users knew very little and even many tech media were Only when we discovered this change today, we must say that the opacity and propaganda of Google’s policy changes are insufficient, and this will undoubtedly touch the nerves of sensitive users of personal information and data.