Apparatus and method for generating random digital value
Provided is an apparatus for generating digital values to provide a random digital value. The apparatus may generate the digital value based on a semiconductor process variation. The apparatus may include a generating unit to generate a plurality of digital values, based on the semiconductor process variation, and a processing unit to process the digital values and to provide a first digital value. The generating unit may include a plurality of physically unclonable functions (PUFs). A parameter may be differently applied to the PUFs, and the PUFs may generate the digital values.
1. An apparatus for generating a digital value, the apparatus comprising:
a generating unit to generate a plurality of digital values, the generating unit comprising a plurality of physically unclonable functions (PUFs), wherein a portion of the PUFs is implemented by applying at least one parameter causing a semiconductor process variation; and
a processing unit to process the digital values and to provide a first digital value,
wherein at least one of the PUFs comprises a via formed between conductive layers in a semiconductor, and
wherein the parameter comprises a size of the via selected from a range between a minimum value and a maximum value of the size of the via corresponding to whether the via causes a short between the conductive layers.
2. The apparatus of claim 1 , wherein at least one of the digital values is generated based on whether the via causes a short between the conductive layers.
3. The apparatus of claim 1 , wherein the size of the via is determined prior to manufacturing the apparatus.
4. The apparatus of claim 1 , wherein the processing unit selects, as the first digital value among the digital values, a digital value that satisfies a condition.
5. The apparatus of claim 1 , wherein the processing unit selects, as the first digital value among the digital values, a value generated by a PUF in which the applied parameter has a minimum value, among a group of PUFs that each provides a digital value corresponding to a bit sequence including both “0” and “1.”
6. The apparatus of claim 1 , wherein the processing unit selects, as the first digital value among the digital values, a value generated by a PUF in which the applied parameter has a median value between a minimum value and a maximum value, among a group of PUFs that each provides a digital value corresponding to a bit sequence including both “0” and “1.”
7. The apparatus of claim 1 , wherein the processing unit performs a logical operation on the digital values for each bit sequence, and calculates the first digital value.
8. The apparatus of claim 7 , wherein the logical operation is an eXclusive OR (XOR) logical operation.
9. A method of generating a digital value by an apparatus for generating a digital value based on a semiconductor process variation, the method comprising:
generating, by a plurality of physically unclonable functions (PUFs), a plurality of digital values, a portion of the PUFs being manufactured by differently applying at least one parameter causing the semiconductor process variation; and
processing, by a processing unit, the digital values and providing a first digital value,
wherein at least one of the PUFs comprises a via formed between conductive layers in a semiconductor, and
wherein the parameter comprises a size of the via selected from a range between a minimum value and a maximum value of the size of the via corresponding to whether the via causes a short between the conductive layers.
10. The method of claim 9 , wherein the generating comprises generating at least one of the digital values based on whether the conductive layers are shorted by the via.
11. The method of claim 10 , wherein the size of the via is determined in a test process performed prior to a process of manufacturing the apparatus, and different via sizes in the range are applied to the PUFs.
12. The method of claim 9 , wherein the processing comprises selecting, as the first digital value among the digital values, a digital value that satisfies a condition.
13. The method of claim 12 , wherein the processing unit selects, as the first digital value among the digital values, a value generated by a PUF in which the applied parameter has a minimum value, among a group of PUFs that each provides a digital value corresponding to a bit sequence including both “0” and “1.”
14. The method of claim 12 , wherein the processing unit selects, as the first digital value among the digital values, a value generated by a PUF in which the applied parameter has a median value between a minimum value and a maximum value, among a group of PUFs that each provides a digital value corresponding to a bit sequence including both “0” and “1.”
15. The method of claim 9 , wherein the processing comprises performing a logical operation on the digital values for each bit sequence, and calculating the first digital value.
16. The method of claim 15 , wherein the logical operation is an eXclusive OR (XOR) logical operation.