A cryptographic device comprising - a non-volatile memory, the non-volatile memory comprising multiple memory cells (210; 310; 350) that are programmed or not-programmed, a range (220; 322; 364) of the memory storing data, - a memory read-out unit configured to operate in a regular read-out mode and a PUF read-out mode, the memory read-out unit comprising - a selector arranged to receive a selector signal, wherein based on the received selector signal, the selector is arranged to configure the memory read-out unit to switch from the regular read-out mode to the PUF read-out mode for reading the same memory, or to switch from the PUF read-out mode to the regular read-out mode for reading the same memory, - in the regular read-out mode, the memory read-out unit being arranged to apply a first voltage to selected memory cells to determine if the cells are programmed or not-programmed, and - in the PUF read-out mode, the memory read-out unit being arranged to apply a second voltage to selected programmed memory cells to read a noisy bit string from the memory, and - a control unit arranged to - send the selector signal to the selector configuring the memory read-out unit in the regular read-out mode, and reading the memory range to obtain the data, and - send the selector signal to the selector configuring the memory read-out unit for the PUF read-out mode, and obtaining a noisy bit string from the memory range. - a non-volatile memory, the non-volatile memory comprising multiple memory cells (210; 310; 350) that are programmed or not-programmed, a range (220; 322; 364) of the memory storing data, - a memory read-out unit configured to operate in a regular read-out mode and a PUF read-out mode, the memory read-out unit comprising - a selector arranged to receive a selector signal, wherein based on the received selector signal, the selector is arranged to configure the memory read-out unit to switch from the regular read-out mode to the PUF read-out mode for reading the same memory, or to switch from the PUF read-out mode to the regular read-out mode for reading the same memory, - in the regular read-out mode, the memory read-out unit being arranged to apply a first voltage to selected memory cells to determine if the cells are programmed or not-programmed, and - in the PUF read-out mode, the memory read-out unit being arranged to apply a second voltage to selected programmed memory cells to read a noisy bit string from the memory, and - a selector arranged to receive a selector signal, wherein based on the received selector signal, the selector is arranged to configure the memory read-out unit to switch from the regular read-out mode to the PUF read-out mode for reading the same memory, or to switch from the PUF read-out mode to the regular read-out mode for reading the same memory, - in the regular read-out mode, the memory read-out unit being arranged to apply a first voltage to selected memory cells to determine if the cells are programmed or not-programmed, and - in the PUF read-out mode, the memory read-out unit being arranged to apply a second voltage to selected programmed memory cells to read a noisy bit string from the memory, and - in the regular read-out mode, the memory read-out unit being arranged to apply a first voltage to selected memory cells to determine if the cells are programmed or not-programmed, and - in the PUF read-out mode, the memory read-out unit being arranged to apply a second voltage to selected programmed memory cells to read a noisy bit string from the memory, and - a control unit arranged to - send the selector signal to the selector configuring the memory read-out unit in the regular read-out mode, and reading the memory range to obtain the data, and - send the selector signal to the selector configuring the memory read-out unit for the PUF read-out mode, and obtaining a noisy bit string from the memory range. - send the selector signal to the selector configuring the memory read-out unit in the regular read-out mode, and reading the memory range to obtain the data, and - send the selector signal to the selector configuring the memory read-out unit for the PUF read-out mode, and obtaining a noisy bit string from the memory range.