Extraction method of physically unclonable function and memory device

A memory device, comprising:

• a memory array comprising a memory block, wherein the memory block comprises a plurality of memory sub-blocks, the memory sub-blocks comprise a plurality of memory cells, the memory cells are divided into a plurality of memory areas, and each of the memory sub-blocks further comprises a string selection line (SSL);
• a memory controller coupled to the memory array;
• a bit line decoder coupled to the memory controller;
• and
• a sub-block selection circuit coupled to the memory controller,
• wherein the memory controller is configured to:
• select a plurality of memory sub-blocks to be chosen among the memory sub-blocks;
• form a combination of the memory sub-blocks to be chosen among the memory sub-blocks to be chosen;
• select a plurality of bits to be chosen among a plurality of bits of a preset memory area in each of the memory sub-blocks to be chosen, wherein the preset memory area is one of the memory areas in each of the memory sub-blocks to be chosen;
• perform a weak PUF processing operation on the preset memory area in each of the memory sub-blocks to be chosen;
• and
• perform a multi-sub-block read operation on the preset memory area in the combination of the memory sub-blocks to be chosen by controlling the bit line decoder and the sub-block selection circuit to extract a PUF data according to the bits to be chosen in the preset memory area read through the multi-sub-block read operation,
• wherein in a condition of performing the multi-sub-block read operation through the memory controller,
• the sub-block selection circuit applies a first SSL cut-off voltage to the string selection line of the memory sub-blocks that are not the memory sub-blocks to be chosen,
• the sub-block selection circuit applies a second SSL cut-off voltage to the string selection line of the memory sub-blocks in the combination that is not selected as the memory sub-blocks to be chosen,
• the sub-block selection circuit applies a selected SSL voltage to the string selection line of the memory sub-blocks in the combination of the memory sub-blocks to be chosen,
• a read voltage is applied to a word line of the preset memory area in the combination of the memory sub-blocks to be chosen,
• a pass voltage is applied to a word line of the memory areas outside the preset memory area in the combination of the memory sub-blocks to be chosen,
• the bit line decoder obtains a plurality of bit line currents according to the preset memory area in the combination of the memory sub-blocks to be chosen, and
• the memory controller determines a bit value of the strong PUF data corresponding to each of the bits to be chosen for the preset memory area based on each of the bit line currents and a sensing current reference value,
• wherein the sensing current reference value is proportional to the number of the memory sub-blocks to be chosen.

An extraction method for a physically unclonable function (PUF), comprising:

• providing a memory block, wherein the memory block comprises a plurality of memory sub-blocks, the memory sub-blocks comprise a plurality of memory cells, the memory cells are divided into a plurality of memory areas, and each of the memory sub-blocks further comprises a string selection line (SSL);
• selecting M memory sub-blocks to be chosen from the memory sub-blocks, wherein M is a positive integer;
• forming a combination of the memory sub-blocks to be chosen among the M memory sub-blocks to be chosen;
• selecting N bits to be chosen among a plurality of bits of a preset memory area in each of the M memory sub-blocks to be chosen, wherein N is a positive integer, the preset memory area is one of the memory areas in each of the M memory sub-blocks to be chosen;
• performing a weak PUF processing operation on the preset memory area in each of the M memory sub-blocks to be chosen;
• and
• performing a multi-sub-block read operation on the preset memory area in the combination of the memory sub-blocks to be chosen to extract a strong PUF data according to the N bits to be chosen in the preset memory area read through the multi-sub-block read operation, comprising:
• applying a first SSL cut-off voltage to the string selection line of the memory sub-blocks that are not the M memory sub-blocks to be chosen;
• applying a second SSL cut-off voltage to the string selection line of the memory sub-blocks in the combination that is not selected as the memory sub-blocks to be chosen;
• applying a selected SSL voltage to the string selection line of the memory sub-blocks in the combination of the memory sub-blocks to be chosen;
• applying a read voltage to a word line of the preset memory area in the combination of the memory sub-blocks to be chosen;
• applying a pass voltage to a word line of the memory areas outside the preset memory area in the combination of the memory sub-blocks to be chosen;
• obtaining a plurality of bit line currents according to the preset memory area in the combination of the memory sub-blocks to be chosen;
• and
• determining a bit value of the strong PUF data corresponding to each of the N bits to be chosen for the preset memory area based on each of the bit line currents and a sensing current reference value,
• wherein the sensing current reference value is proportional to the number of the memory sub-blocks to be chosen.