US 12,445,271 B2
Electronic device and public key replacement method thereof
Wen-Shuo Chang, Hsinchu (TW)
Assigned to NUVOTON TECHNOLOGY CORPORATION, Hsinchu Science Park (TW)
Filed by Nuvoton Technology Corporation, Hsinchu Science Park (TW)
Filed on Jan. 29, 2024, as Appl. No. 18/425,434.
Claims priority of application No. 112140090 (TW), filed on Oct. 20, 2023.
Prior Publication US 2025/0132900 A1, Apr. 24, 2025
Int. Cl. H04L 9/40 (2022.01); H04L 9/08 (2006.01)
CPC H04L 9/0825 (2013.01) 20 Claims
OG exemplary drawing
 
1. An electronic device, comprising:
an immutable memory, storing a first public key and a second public key in advance, wherein the first public key and the second public key are unmodifiable;
a counter, having an anti-rollback protection and counting a count value; and
a processor, selecting the first public key, the second public key, or both, based on the count value;
wherein when the count value is a first value, the processor selects the first public key corresponding to the first value;
wherein when the count value is a second value, the processor selects the second public key corresponding to the second value;
wherein when the count value is a third value, the processor selects the first public key and the second public key;
wherein the third value is an average of the first value and the second value, and the second value exceeds the first value;
wherein the first value and the second value are in a first state and the third value is in a second state;
wherein the first state and the second state are different.