MIFARE Classic 1K Access Bits Calculator

Decode: You can modify the "Access bits" and the Data Block and Sector Trailer tables will automatically update.

Encode: Click the "Edit" button in each row of the table to select your preferred access conditions. This will update the Access Bits.

Warning

Writing an incorrect value to the access condition bits can make the sector inaccessible.

Access Bits

Data Block Access Conditions:

Block C1Y C2Y C3Y Read Write Increment Decrement/Transfer/Restore Remarks Action
Block 0 0 0 0 key A|B key A|B key A|B key A|B Default configuration
Block 1 0 0 0 key A|B key A|B key A|B key A|B Default configuration
Block 2 0 0 0 key A|B key A|B key A|B key A|B Default configuration
C1Y C2Y C3Y Read Write Increment Decrement/Transfer/Restore Remarks
0 0 0 key A|B key A|B key A|B key A|B Default configuration
0 1 0 key A|B never never never read/write block
1 0 0 key A|B key B never never read/write block
1 1 0 key A|B key B key B key A|B value block
0 0 1 key A|B never never key A|B value block
0 1 1 key B key B never never read/write block
1 0 1 key B never never never read/write block
1 1 1 never never never never read/write block

Sector Trailer (Block 3) Access Conditions:

C13 C23 C33 Read Key A Write Key A Read Access Bits Write Access Bits Read Key B Write Key B Remarks Action
0 0 1 never key A key A key A key A key A Key B may be read; Default configuration
C13 C23 C33 Read Key A Write Key A Read Access Bits Write Access Bits Read Key B Write Key B Remarks
0 0 0 never key A key A never key A key A Key B may be read
0 1 0 never never key A never key A never Key B may be read
1 0 0 never key B key A|B never never key B
1 1 0 never never key A|B never never never
0 0 1 never key A key A key A key A key A Key B may be read; Default configuration
0 1 1 never key B key A|B key B never key B
1 0 1 never never key A|B key B never never
1 1 1 never never key A|B never never never

References