# US 2026/0074902 A1 · Device, Storage Device and Method for Switching Encryption Algorithm > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2026/0074902 A1 - Document ID: US20260074902A1 - Status: Published application - Kind: A1 - Application number: 19/325,110 - Filed: 2025-09-10 - Published: 2026-03-12 - Earliest claimed: 2024-09-12 - Assignees: Samsung Electronics Co., Ltd. - Applicants: Samsung Electronics Co., Ltd. - Inventors: Youngtak Noh; Sungho Yoon; Younsung Chu; Myeongjin Moon; Moon Chan Park; Yejin Yoon; Sunghyun Jin - Web page: https://patentgrep.com/patent/US20260074902A1 ## CPC - H04L 9/16: the keys or algorithms being changed during operation - G06F 8/65: Updates (security arrangements therefor G06F21/57) - G06F 21/572: {Secure firmware programming, e.g. of basic input output system [BIOS]} - H04L 9/3247: {involving digital signatures} - G06F 2221/033: Test or assess software - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) ## Abstract A device includes a memory and a processor configured to receive, from a host, a first signature that is based on a first cryptographic algorithm, a second signature that is based on a second cryptographic algorithm, and firmware, verify the first signature based on a first public key for decrypting the first signature and a hash value associated with the firmware, and write a second public key that is included in the firmware into the memory in response to successful verification of the first signature. ## Claims ### Claim 1 A device comprising: a memory; and a processor configured to: receive, from a host, a first signature that is based on a first cryptographic algorithm, a second signature that is based on a second cryptographic algorithm, and firmware; verify the first signature based on a first public key for decrypting the first signature and a hash value associated with the firmware; and write, in response to successful verification of the first signature, a second public key that is included in the firmware into the memory. ### Claim 2 (depends on 1) The device of claim 1, wherein the processor is configured to verify the first signature based on the first cryptographic algorithm for the first public key and the hash value. ### Claim 3 (depends on 1) The device of claim 1, wherein the processor is configured to: verify the second signature based on the second public key that is written in the memory and the hash value; and update previously installed firmware to the received firmware in response to successful verification of the second signature. ### Claim 4 (depends on 3) The device of claim 3, wherein the processor is configured to verify the second signature based on the second cryptographic algorithm for the second public key and the hash value. ### Claim 5 (depends on 3) The device of claim 3, wherein the processor is configured to invalidate the first public key in response to successful verification of the second signature. ### Claim 6 (depends on 1) The device of claim 1, wherein the memory is a one-time programmable (OTP) memory. ### Claim 7 (depends on 6) The device of claim 6, wherein the memory is configured to store the first public key, the first public key including a plurality of bits, and the processor is configured to: verify the second signature based on the second public key that is written in the memory and the hash value; and change, in response to successful verification of the second signature, one or more bits of the plurality of bits of the first public key from a first logic level to a second logic level. ### Claim 8 (depends on 6) The device of claim 6, wherein the memory stores the first public key at a first index, and the processor is configured to write the second public key at a second index having a greater value than the first index. ### Claim 9 (depends on 1) The device of claim 1, wherein the first cryptographic algorithm is an elliptic curve digital signature algorithm (ECDSA), and the second cryptographic algorithm is Leighton-Micali Hash-Based signatures (LMS) algorithm. ### Claim 10 (depends on 1) The device of claim 1, wherein the processor is configured to, in response to unsuccessful verification of the first signature, discard the first signature, the second signature, and the firmware. ### Claim 11 (depends on 3) The device of claim 3, wherein the processor is configured to, in response to unsuccessful verification of the second signature, perform a recovery operation based on the first public key. ### Claim 12 (depends on 3) The device of claim 3, wherein the processor is configured to: after updating the previously installed firmware to the received firmware, receive, from the host, another version of the firmware and the second signature; verify the second signature based on the second public key and a hash value associated with the another version of the firmware; and perform, in response to unsuccessful verification of the second signature for the another version of the firmware, a recovery operation based on the second public key. ### Claim 13 A storage device comprising: a non-volatile memory configured to store a first signature that is based on a first cryptographic algorithm, a second signature that is based on a second cryptographic algorithm, and firmware; and a storage controller configured to verify the first signature based on a first public key for decrypting the first signature and a hash value associated with the firmware, and update, in response to successful verification of the first signature, a second public key that is included in the firmware into the storage device. ### Claim 14 (depends on 13) The storage device of claim 13, further comprising: a key memory configured to store the second public key. ### Claim 15 (depends on 14) The storage device of claim 14, wherein the storage controller is configured to write the second public key in the key memory in response to successful verification of the first signature. ### Claim 16 A method of operating a device, the method comprising: receiving, from a host, a first signature generated based on a first cryptographic algorithm, a second signature generated based on a second cryptographic algorithm, and firmware; verifying the first signature based on a first public key for decrypting the first signature and a hash value associated with the firmware; and writing, in response to successful verification of the first signature, a second public key that is included in the firmware into a memory. ### Claim 17 (depends on 16) The method of claim 16, further comprising: verifying the second signature based on the second public key that is written in the memory and the hash value; and updating previously installed firmware to the received firmware in response to successful verification of the second signature. ### Claim 18 (depends on 17) The method of claim 17, further comprising: invalidating the first public key in response to successful verification of the second signature. ### Claim 19 (depends on 17) The method of claim 17, further comprising: performing, in response to unsuccessful verification of the second signature, a recovery operation based on the first public key. ### Claim 20 (depends on 17) The method of claim 17, further comprising: after updating the previously installed firmware to the received firmware, receiving, from the host, another version of the firmware and the second signature; verifying the second signature based on the second public key that is written in the memory and a hash value associated with the another version of the firmware; and performing, in response to unsuccessful verification of the second signature for the another version of the firmware, a recovery operation based on the second public key.