Making Mifare Ulralight Write protected in Android

i write some data (NDEF) into Mifare Ultralight Tag. Then the tag is set to read only with Ndef.MakeReadOnly(). The Tag seems to be read only afterwards.

But reading the Tag content shows, that only pages (4-15, Lx bytes are set to 1) are locked, the three BLx Bytes are left 0. When i got it right, this means that Pages Locks could be altered again. Page 2, Bytes 2 = 11111000, Page 2 Byte 3 = 11111111 - (see http://www.nxp.com/documents/data_sheet/MF0ICU1.pdf , page 12).

Is the开发者_如何学运维re a way to make the tag permanently write protected?

Thanks for your time.

To make the whole tag read only, you could get the tag again as a MifareUltralight instead of as a Ndef. Then you do

MifareUltralightTag.writePage(2,new byte[] {0x00, 0x00, 0xFF, 0xFF}); 

followed by

MifareUltralightTag.transceive(new byte[] {0x26}); 

to "activate the new locking configuration."