KR20230131750A - Storage device and method thereof - Google Patents

Abstract

A storage device according to an embodiment includes a memory including a firmware image area, a firmware signature, firmware data, and a first certificate including a first certificate public key and a firmware fingerprint for verifying the firmware signature, and a first certificate. Receive a first firmware image including a second certificate including a second certificate public key for verifying, verify the first certificate using the second certificate public key, and when verification of the first certificate is completed , Compare whether the hash value of the firmware data and the firmware fingerprint match, and if the hash value of the firmware data and the firmware fingerprint match, the firmware signature is verified using the first certificate public key, and if the firmware signature is verified, the firmware signature is verified. 1 Includes a memory controller that stores the firmware image in the firmware image area.

Description

Storage device and method of operation thereof {STORAGE DEVICE AND METHOD THEREOF}

The disclosure relates to storage devices and methods of operating the same.

A storage device can be driven through firmware. Firmware may be stored in ROM (Read Only Memory) of a storage device. Firmware may be modified or updated.

When the storage device receives an updated firmware image from the host, the storage device can verify whether the received firmware image is valid. If there is no problem with the firmware image, the storage device can perform an update using the firmware image. The storage device can verify whether the firmware image is valid by verifying the firmware signature using a public key indicated by a value stored in OTP memory (One-Time Programmable Memory), among several public keys stored in the ROM of the storage device.

One embodiment is intended to provide a storage device and a method of operating the same that can verify a firmware image without updating the OTP memory even if the secret key used to generate the firmware signature is leaked.

A storage device according to an embodiment to solve this technical challenge includes a memory including a firmware image area, a firmware signature, firmware data, and a first certificate public key and firmware fingerprint for verifying the firmware signature. Receive a first firmware image including a first certificate and a second certificate including a second certificate public key for verifying the first certificate, verify the first certificate using the second certificate public key, and 1 When verification of the certificate is completed, compare the hash value of the firmware data and the firmware fingerprint to see if they match. If the hash value of the firmware data and the firmware fingerprint match, the firmware signature is verified using the first certificate public key. , and a memory controller that stores the first firmware image in the firmware image area when the firmware signature is verified.

If the hash value of the firmware data and the firmware fingerprint do not match, the memory controller may determine that the firmware image has been manipulated.

A second firmware image of the storage device is stored in the firmware image area, each of the second firmware image and the first firmware image includes firmware key version information, and the memory controller determines that the firmware key version of the first firmware image is the second firmware If the firmware key version of the image is higher than the firmware key version, it may be compared to determine whether the hash value of the firmware data of the first firmware image and the firmware fingerprint of the first firmware image match.

If the firmware key version of the first firmware image is lower than the firmware key version of the second firmware image, the memory controller may determine that the version of the first firmware image is lower than the version of the second firmware image.

When verification of the first certificate is completed, the memory controller may compare the key versions of the second firmware image and the first firmware image.

It may further include a ROM for storing a public key, and the memory controller may verify the second certificate using the public key stored in the ROM, and may verify the first certificate when verification of the second certificate is completed.

The first certificate includes the signature of the first certificate, the second certificate includes the signature of the second certificate, and the signature of the first certificate and the signature of the second certificate may be generated with the same private key.

The memory controller can verify the signature of the second certificate using the public key stored in the ROM.

The memory controller may verify the signature of the first certificate using the second certificate public key.

A method of updating firmware of a storage device according to an embodiment includes a first firmware image including a firmware signature, firmware data, and a first certificate including a firmware fingerprint and a first certificate public key for verifying the firmware signature from a host. receiving, applying a hash function to the firmware data to obtain a hash value, comparing whether the hash value and the firmware fingerprint match, if the hash value of the firmware data and the firmware fingerprint match, the first It includes verifying the firmware signature using the certificate public key, and once the firmware signature is verified, storing the first firmware image in the firmware image area.

If the hash value of the firmware data and the firmware fingerprint do not match, a step of determining that the firmware image has been manipulated may be further included.

Further comprising comparing the firmware key version of the first firmware image with the firmware key version of the second firmware image stored in the firmware image area of the storage device, wherein the firmware key version of the first firmware image is the firmware image of the storage device. If the firmware key version of the second firmware image stored in the area is higher than the firmware key version, a step of obtaining a hash value can be performed.

If the firmware key version information of the first firmware image is lower than the firmware key version information of the second firmware image, the method may further include determining that the version of the first firmware image is lower than the version of the second firmware image.

The firmware image further includes a second certificate including a second certificate public key for verifying the first certificate, and the firmware update method further includes verifying the first certificate using the second certificate public key. , When verification of the first certificate is completed, a step of comparing the firmware key version of the first firmware image with the firmware key version of the second firmware image stored in the firmware image area of the storage device can be performed.

A step of verifying the second certificate using a public key stored in the ROM of the storage device may be further included, and when verification of the second certificate is completed, a step of verifying the first certificate may be performed.

The first certificate includes the signature of the first certificate, the second certificate includes the signature of the second certificate, and the signature of the first certificate and the signature of the second certificate may be generated with the same private key.

Verifying the second certificate may include verifying the signature of the second certificate using a public key stored in the ROM.

Verifying the first certificate may include verifying the signature of the first certificate using the second certificate public key.

A storage device according to an embodiment controls a plurality of memory systems and a plurality of memory systems, receives a firmware image including firmware data and a firmware fingerprint from a host through a signal connector, and receives a hash value of the firmware data and a firmware fingerprint. If the firmware fingerprints do not match, it includes a controller that reports to the host that the firmware image has been tampered with.

The firmware image includes the signature of a certificate based on the firmware fingerprint, and if the hash value of the firmware fingerprint and the hash value obtained by decrypting the signature of the certificate do not match, the controller may report to the host that the firmware image has been manipulated.

1 is an example block diagram of a storage system according to one embodiment.
Figure 2 is a block diagram showing a storage device according to an embodiment.
Figure 3 is a flowchart showing a method of operating a storage device according to an embodiment.
Figure 4 is an example diagram for explaining firmware of a storage device according to an embodiment.
Figure 5 is a flowchart showing a method of operating a storage system according to an embodiment.
6 to 8 are diagrams explaining the operation of a memory controller according to an embodiment.
FIG. 9 is a block diagram illustrating an example of applying a storage device according to an embodiment to a solid-state drive (SSD) system.

Below, with reference to the attached drawings, embodiments of the present invention will be described in detail so that those skilled in the art can easily implement the present invention. However, the present invention may be implemented in many different forms and is not limited to the embodiments described herein.

In order to clearly explain the present invention in the drawings, parts that are not related to the description are omitted, and similar parts are given similar reference numerals throughout the specification. In the flowchart described with reference to the drawings, the order of operations may be changed, several operations may be merged, certain operations may be divided, and certain operations may not be performed.

Additionally, expressions written in the singular may be interpreted as singular or plural, unless explicit expressions such as “one” or “single” are used. Terms containing ordinal numbers, such as first, second, etc., may be used to describe various components, but the components are not limited by these terms. These terms may be used for the purpose of distinguishing one component from another.

1 is an example block diagram of a storage system according to one embodiment.

Referring to FIG. 1, the storage system 100 may include a host 110 and a storage device 120.

The host 110 may transmit firmware to the storage device 120. The storage device 120 may control the storage device 120 or hardware within the storage device 120 based on the received firmware. If firmware already exists in the storage device 120 and an updated version of the existing firmware is received, the storage device 120 may be updated with the newly received firmware.

For example, the host 110 may transmit a firmware image download request (FW UPDATE REQ) (or a firmware image download command (FW DL CMD)) and a firmware image to be downloaded (FW IMAGE) to the storage device 120. there is.

As another example, the host 110 may store a firmware image download command in the submission queue of the host 110. At this time, information on the firmware image 111 for the firmware image download command may be stored together in the submission queue. The storage device 120 may obtain the firmware image 111 based on information stored in the submission queue. The host 110 can transmit the firmware image 111 to the storage device 120 in various ways, and the transmission method is not limited to one.

The host 110 may transmit a firmware update request for the transmitted firmware image 111 to the storage device 120.

Firmware may be in the form of an image. Accordingly, the firmware provided by the host 110 to the storage device 120 may be referred to as the firmware image 111. The firmware image 111 may include a firmware signature 112. In some embodiments, the firmware signature 112 may be generated using the firmware image 111 and the manufacturer's secret key. The firmware image 111 may include a plurality of certificates 113 and 114. In some embodiments, multiple certificates 113, 114 may each include a signature generated with the same secret key. One of the plurality of certificates 113 and 114 (114) may include a public key for the firmware signature (112). One of the plurality of certificates 113 and 114 (113) may include a public key that can verify the other certificate (114). The firmware image 111 may include a firmware fingerprint 115. In some embodiments, one of the plurality of certificates 113, 114 may include a firmware fingerprint 115. The firmware fingerprint 115 may include a hash value of the firmware binary.

The storage device 120 may include a memory controller 121 and a memory 122.

The memory controller 121 may verify the firmware image 111 provided from the host 110. The memory controller 121 may perform an integrity check or a validity check. As an example of an integrity check, a checksum method, a hash function method, a digital signature method, or a MAC (Message Authentication Code) method may be used. The type of verification is not limited to any one. In some embodiments, the memory controller 121 completes verification of the plurality of certificates 113 and 114 and generates a public key for the firmware signature 112 included in any one of the plurality of certificates 113 and 114. Using this, the firmware signature 112 of the firmware image 111 can be verified. In some embodiments, the memory controller 121 may use the fingerprint 115 to verify whether the firmware image 111 has been tampered with. For example, the memory controller 121 may generate a binary hash value of the firmware image 111 and compare it with the firmware fingerprint 115 to verify the firmware image 111.

The memory controller 121 may store the verified firmware image 111 in the memory 122 in response to a firmware update request. When verification of the firmware signature 112 is completed, the memory controller 121 may update the firmware image 111.

The storage device 120 may include storage media for storing data according to a request from the host 110. As an example, the storage device 120 may include one or more solid state drives (SSDs). When the storage device 120 includes an SSD, the memory 122 may include a plurality of flash memory chips (eg, NAND memory chips) that non-volatilely store data. Meanwhile, the memory 122 may correspond to one flash memory device, or the memory 122 may include a memory card including one or more flash memory chips.

When the storage device 120 includes flash memory, the flash memory may include a 2D NAND memory array or a 3D (or vertical) NAND (VNAND) memory array. A 3D memory array is an array of memory cells having an active area disposed on a silicon substrate, or circuitry associated with the operation of the memory cells, and is formed monolithically on at least one physical level of a circuit formed on or within a substrate. The term “monolithic” means that the layers of each level of the array are stacked directly on top of the layers of each lower level of the array. A 3D memory array includes vertical NAND strings arranged in a vertical direction so that at least one memory cell is located on top of other memory cells. At least one memory cell may include a charge trap layer.

As another example, the storage device 120 may include various other types of memories. For example, the storage device 120 may include non-volatile memory, which may include magnetic RAM (MRAM), spin-transfer torque MRAM (Spin-Transfer Torque MRAM), conductive bridging RAM (CBRAM), and FeRAM ( Ferroelectric RAM, PRAM (Phase RAM), Resistive RAM, Nanotube RAM, Polymer RAM (PoRAM), Nano Floating Gate Memory (NFGM), Holographic Memory Various types of memory can be applied, such as holographic memory, molecular electronics memory, or insulation resistance change memory.

The memory 122 may be an embedded Multi-Media Card (eMMC) or an embedded Universal Flash Storage (UFS) memory device. For example, the memory 122 may be an external memory that is removable from the storage device 120 . Specifically, the memory 122 may be a UFS memory card, Compact Flash (CF), Secure Digital (SD), Micro Secure Digital (Micro-SD), Mini Secure Digital (Mini-SD), extreme Digital (xD), or memory stick. It may be a (Memory Stick), but is not limited thereto.

The host 110 may communicate with the storage device 120 through various interfaces. As an example, the host 110 supports Universal Serial Bus (USB), MultiMediaCard (MMC), PCIExpress (PCI-E), AT Attachment (ATA), Serial AT Attachment (SATA), Parallel AT Attachment (PATA), and SCSI ( Communicate with the storage device 120 through various interfaces such as Small Computer System Interface (SAS), Serial Attached SCSI (SAS), Enhanced Small Disk Interface (ESDI), Integrated Drive Electronics (IDE), and Non-Volatile Memory Express (NVMe). You can.

Figure 2 is a block diagram showing a storage device according to an embodiment.

Referring to FIG. 2 , the storage device 200 may include a system bus 205, a memory controller 210, a ROM 220, a first memory 230, and a memory 240.

The memory controller 210 may control the overall operation of the ROM 220 and memory 230. For example, the memory controller 210 may receive data, addresses, and commands from the host, and control the operation of the memory 230 in response.

ROM 220 may include a public key 221. The public key 221 may be stored in the ROM 220 during the manufacturing process of the storage device 200.

The memory 230 may include a user data area 231 and a firmware image area 232. The user data area 231 may be an area that can be accessed by the host. For example, the user data area 231 may be an area where data is written and read by the memory controller 210 according to a command such as read or write provided from the host. That is, the user data area 231 may be most of the area in the memory 230 where data is written and stored.

The firmware image area 232 may be an area where access by the host is restricted. The firmware image area 232 may store the firmware image 233. The firmware image 233 may be stored in the firmware image area 232 during the manufacturing process of the storage device 200. Alternatively, a new firmware image may be stored in the firmware image area 232 by updating the firmware after the storage device 200 is shipped.

Memory 230 may include non-volatile memory. The memory 230 includes, for example, NAND flash memory, vertical NAND (VNAND, 3D), NOR flash memory, and PRAM (Phase-Change Random Access Memory). , Resistive Random Access Memory (RRAM), Magnetoresistive Random Access Memory (MRAM), Ferroelectric Random Access Memory (FRAM), Spin Transfer Torque Random Access Memory (STT-RAM), or similar non-volatile memory devices. However, this embodiment is not limited to this.

The system bus 205 may perform a connection between the memory controller 210, ROM 220, and memory 230.

Figure 3 is a flowchart showing a method of operating a storage device according to an embodiment.

Referring to Figures 2 and 3, the memory controller 210 receives a firmware image download command and a firmware image to be downloaded from the host (S300).

The memory controller 210 verifies the certificate in the received firmware image (S310). In some embodiments, the memory controller 210 may use the public key 221 stored in the ROM 220 to verify a certificate in the firmware image. When verification of the certificate is completed, the memory controller 210 may obtain a public key to verify the firmware signature included in the verified certificate.

The memory controller 210 verifies the firmware fingerprint in the firmware image (S320). In some embodiments, memory controller 210 may generate a hash value for the firmware binary code of the firmware image. The memory controller 210 may compare the generated hash value and the firmware fingerprint to verify the firmware fingerprint.

If verification of the firmware fingerprint fails, the memory controller 210 may determine that the firmware image has been manipulated. Additionally, the memory controller 210 may report to the host that the firmware image has been manipulated. Then, the host can report to the manufacturer that the firmware image has been manipulated and that the secret key used to sign the firmware of the firmware image has been leaked. The memory controller 210 verifies the firmware signature in the received firmware image (S330). In some embodiments, the memory controller 210 may verify the firmware signature using the public key obtained in step S310.

When verification of the firmware signature is completed, the memory controller 210 updates the firmware image (S340). For example, if verification of the firmware signature is successful, the memory controller 210 stores the verified firmware image in the firmware image area 232 of the memory 230 and stores the received firmware image in the storage device 200. You can update firmware. As another example, if verification of the firmware signature fails, the memory controller 210 may not store the firmware image in the memory 230.

Figure 4 is an example diagram for explaining firmware of a storage device according to an embodiment.

Referring to FIG. 4 , the firmware image 400 may include a firmware signature 410, firmware data 420, and a plurality of certificates 430 and 440.

The firmware signature 410 may include information necessary to verify the firmware image 400. The firmware signature 410 may have different information depending on the digital signature algorithm (DSA) applied to the firmware image 400. A digital signature algorithm may refer to an algorithm that generates a signature on given data using a secret key known only to the user. A third party can confirm that the data was created by a verified person through signature verification using the public key for verification. For example, when authentication according to the RSA (Rivest Shamir Adleman) algorithm is performed on the firmware image 400, the result of signing the hash value obtained by applying a hash function to the firmware data 420 with a secret key is the firmware signature ( 410). The firmware signature 410 can be verified with a public key included in one of the plurality of certificates 430 and 440 that are related to each other.

Firmware data 420 may include firmware program code.

The first certificate 430 may include a first certificate signature 431 and a first certificate public key 432. The first certificate signature 431 may include a result signed by the manufacturer's private key. The first certificate signature 431 can be verified using the public key stored in the ROM of the storage device. The first certificate 430 is a root of trust (RoT), and the storage device verifies the first certificate signature 431 to verify that the first certificate 430 is a trustworthy certificate generated by the manufacturer's secret key. can do.

The second certificate 440 may include a second certificate signature 441, a second certificate public key 442, a firmware fingerprint 443, and firmware key version information 444. The second certificate signature 441 may include a result signed by the manufacturer with a private key. The second certificate signature 441 can be verified with the first certificate public key 432.

The firmware fingerprint 443 may include a binary hash value of the firmware data 420. In some embodiments, firmware fingerprint 443 may include a hash value calculated by applying a hash function to the binary of firmware data 420.

The firmware key version information 444 may include version information of the secret key used to generate the firmware signature 410 when creating the firmware image 400. If the secret key used to generate the firmware signature 410 is leaked, the firmware signature 410 is created with a new secret key by the manufacturer, and the version of the secret key may be changed.

Figure 5 is a flowchart showing a method of operating a storage system according to an embodiment.

Referring to FIG. 5, the host requests a firmware image download to the storage device (S500). The host can transmit the image download command and the firmware image to be downloaded to the storage device.

The storage device receives a new firmware image from the host (S510). The storage device may store the new firmware image in an area of memory.

The memory controller of the storage device verifies the signature of the first certificate of the received firmware image using the public key stored in the ROM (S520).

If verification of the signature of the first certificate is successful, the memory controller of the storage device verifies the signature of the second certificate of the received firmware image using the public key of the first certificate included in the first certificate (S530). The memory controller of the storage device decrypts the hash value of the data included in the second certificate (firmware fingerprint, firmware key version information, and firmware signature) and the signature of the second certificate using the public key of the first certificate. You can verify that the values match. If the private key that signed the second certificate is not leaked, but the firmware fingerprint is manipulated, the hash value of the data contained in the second certificate and the public key of the first certificate are used to decrypt the signature of the second certificate. Because the values do not match, verification of the second certificate's signature fails.

If verification of the signature of the second certificate is successful, the memory controller of the storage device determines whether the key version of the new firmware is a version higher than the existing firmware key version (S540).

If the key version of the new firmware is a version higher than the existing firmware key version, the memory controller of the storage device generates a hash value for the binary of the firmware data of the received firmware image (S550).

The memory controller of the storage device compares the hash value and the firmware fingerprint of the received firmware image (S560).

If the hash value and the firmware fingerprint of the received firmware image are the same, the memory controller of the storage device verifies the firmware signature of the received firmware image using the public key of the second certificate included in the second certificate (S570).

If verification of the firmware signature is successful, the memory controller of the storage device records the received firmware image in the firmware image area and performs an update (S580).

If verification of the signature of the first certificate fails in step S520, and if verification of the signature of the second certificate fails in step S530, the key version of the new firmware is changed to the existing firmware key in step S540. If it is less than the version, if the hash value in step S560 and the firmware fingerprint of the received firmware image are different, or if verification of the firmware signature fails in step S570, the memory controller of the storage device stops updating the firmware. (S582) Do.

In step S540, if the key version of the new firmware is lower than the existing firmware key version, the memory controller of the storage device determines that the version of the firmware image to the host is lower than the version of the firmware image stored in the storage device and reports this to the host. You can.

If the hash value and the firmware fingerprint of the received firmware image are different in step S560, the memory controller of the storage device may report to the host that the firmware image has been manipulated. The host can report to the manufacturer that the firmware image has been manipulated and that the secret key used to sign the firmware in the firmware image has been leaked.

In response to the firmware download request, the memory controller of the storage device transmits a completion indication indicating success or failure of the firmware update to the host (S590).

6 to 8 are diagrams explaining the operation of a memory controller according to an embodiment.

Figure 6 is a diagram showing the update of a general firmware image. Referring to FIG. 6, the storage device 650 may receive a normal firmware image 600 and perform a firmware image update. The normal firmware image 600 may be an image manufactured when the secret key that created the firmware signature has not been leaked. Accordingly, the firmware key version 644 of the new firmware image 600 has not changed.

The memory controller 655 can verify the signature 631 of the first certificate 630 using the public key 661 stored in the ROM 660 (①).

When verification of the signature 631 of the first certificate 630 is completed, the memory controller 655 verifies the signature 641 of the second certificate using the public key 632 of the first certificate 630. You can (②).

When verification of the signature 641 of the second certificate 640 is completed, the memory controller 655 updates the firmware key version stored in the second certificate 674 of the firmware image stored in the memory 670 and the new firmware image 600. ) You can compare the firmware key version (644) (③).

Since the firmware key version 644 of the new firmware image 600 is the same as the firmware key version stored in the second certificate 674 of the firmware image stored in memory 670, the memory controller 655 A hash value for the binary can be generated and compared with the firmware fingerprint (643) (④).

Since the hash value and the firmware fingerprint 643 are the same, the memory controller 655 can verify the firmware signature using the public key 642 of the second certificate 640 (⑤).

Figure 7 is a diagram showing the update of the firmware image by updating the secret key when the secret key that created the firmware signature is leaked. Referring to FIG. 7, the storage device 750 may receive a firmware image 700 with an updated secret key and perform a firmware image update. The firmware key version 744 of the new firmware image 700 is updated.

The memory controller 755 can verify the signature 731 of the first certificate 730 using the public key 761 stored in the ROM 760 (①).

When verification of the signature 731 of the first certificate 730 is completed, the memory controller 755 uses the public key 732 of the first certificate 730 to verify the signature 741 of the second certificate 740. can be verified (②).

When verification of the signature 741 of the second certificate 740 is completed, the memory controller 755 stores the firmware key version stored in the second certificate 774 of the firmware image stored in the memory 770 and the new firmware image 700. ) You can compare the firmware key version (744) (③).

Since the firmware key version 744 of the new firmware image 700 is higher than the firmware key version stored in the second certificate 774 of the firmware image stored in memory 770, the memory controller 755 A hash value for the binary can be generated and compared with the firmware fingerprint (743) (④).

Since the hash value and the firmware fingerprint 743 are the same, the memory controller 755 can perform verification of the firmware signature using the public key 742 of the second certificate 740 (⑤).

Figure 8 is a diagram illustrating the update of a firmware image with a maliciously manipulated firmware signature when the private key that created the firmware signature is leaked. Referring to FIG. 8, the storage device 850 may receive a firmware image 800 with a maliciously manipulated firmware signature. However, the storage device 850 may not perform firmware image update through firmware image verification. The firmware image 800 may be an image in which the firmware signature 810 and firmware data 820 have been manipulated.

The secret key used for the firmware signature 810 may be leaked, and in this case, the firmware signature 810 and firmware data 820 may be manipulated. However, since the secret key used to generate the first certificate 830 and the second certificate 840, that is, the secret key of the first certificate 830 is not leaked, the first certificate 830 and the second certificate ( 840) cannot be manipulated. Accordingly, the firmware fingerprint 843 and information 844 about the firmware key version included in the first certificate 830 and the second certificate 840 cannot be manipulated. Therefore, the manipulated firmware image 800 may include a manipulated firmware signature 810, a manipulated firmware data 820, a normal first certificate 830, and a normal second certificate 840.

The memory controller 855 can verify the signature 831 of the first certificate 830 using the public key 861 stored in the ROM 860 (①).

When verification of the signature 831 of the first certificate 830 is completed, the memory controller 855 uses the public key 832 of the first certificate 830 to verify the signature 841 of the second certificate 840. can be verified (②).

When verification of the signature 841 of the second certificate 840 is completed, the memory controller 855 stores the firmware key version stored in the second certificate 874 of the firmware image stored in the memory 870 and the new firmware image 800. ) You can compare the firmware key version (844) (③).

Since the firmware key version 844 of the new firmware image 800 is the same as the firmware key version stored in the second certificate 874 of the firmware image stored in memory 870, the memory controller 855 A hash value for the binary can be generated and compared with the firmware fingerprint (843) (④).

Since the hash value of the manipulated firmware data 820 is different from the normal firmware fingerprint 843, the memory controller 855 may stop updating the firmware image 800.

Conventionally, all public keys to be used for firmware signature verification during the entire lifespan of the storage device are stored in the ROM of the storage device, and among these public keys, the public key indicated by the value stored in the OTP memory is selected and used for firmware signature verification. . Therefore, it depends on the hardware called OTP memory, and there is a limitation that the number of public keys stored in ROM can be changed and used.

In one embodiment, one public key can be stored and used in the ROM of the storage device, so even if the private key used to generate the firmware signature is leaked, replacement of the public key is not required, and a separate OTP memory is also required. Not required.

According to one embodiment, even if the secret key used to generate the firmware signature is leaked, information for verifying the firmware image (e.g., firmware fingerprint and firmware key version information) is included in the plurality of certificates. , it is possible to prevent firmware updates of storage devices using manipulated firmware images.

According to one embodiment, if the firmware fingerprint is manipulated, verification of the second certificate fails, thereby preventing firmware update of the storage device using the manipulated firmware image.

FIG. 9 is a block diagram illustrating an example of applying a storage device according to an embodiment to a solid-state drive (SSD) system.

Referring to FIG. 9 , the SSD system 900 may include a host 910 and an SSD 920.

SSD 920 may be implemented using the embodiments described with reference to FIGS. 1 to 8 . The SSD 920 can exchange signals with the host 910 through a signal connector (SGL) and receive power through a power connector (PWR).

The SSD 920 can receive a firmware image download command and a firmware image to be downloaded through a signal connector (SGL).

The SSD 920 may include a controller 921, an auxiliary power device 922, and a plurality of memory systems 923, 924, and 925. Each of the plurality of memory systems 923, 924, and 925 may include one or more flash memory devices as storage devices. Additionally, each flash memory device may include one or more dies (DIE), and one or more blocks may be disposed on each die (DIE).

The controller 921 may communicate with a plurality of memory systems 923, 924, and 925 through a plurality of channels (Ch1,..., Chn). The controller 921 may verify the firmware image within the SSD 920 and perform an update operation based on the firmware image.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements made by those skilled in the art using the basic concept of the present invention defined in the following claims are also possible. It falls within the scope of rights.

Claims (10)

memory containing the firmware image area, and
a first certificate comprising a firmware signature, firmware data, and a first certificate public key and a firmware fingerprint for verifying the firmware signature, and a second certificate comprising a second certificate public key for verifying the first certificate. Receive a first firmware image including, verify the first certificate using the second certificate public key, and when verification of the first certificate is completed, the hash value of the firmware data and the firmware fingerprint match compare whether the hash value of the firmware data matches the firmware fingerprint, and if the hash value of the firmware data matches the firmware fingerprint, the firmware signature is verified using the first certificate public key, and if the firmware signature is verified, the first firmware image is sent to the firmware Memory controller that saves to the image area
A storage device containing a. According to paragraph 1,
If the hash value of the firmware data and the firmware fingerprint do not match, the memory controller determines that the firmware image has been manipulated.
Storage device. According to paragraph 1,
A second firmware image of the storage device is stored in the firmware image area,
Each of the second firmware image and the first firmware image includes firmware key version information,
If the firmware key version of the first firmware image is higher than the firmware key version of the second firmware image, the memory controller determines whether the hash value of the firmware data of the first firmware image and the firmware fingerprint of the first firmware image match. To compare whether,
Storage device. According to paragraph 3,
If the firmware key version of the first firmware image is lower than the firmware key version of the second firmware image, the memory controller determines that the version of the first firmware image is lower than the version of the second firmware image.
Storage device. According to paragraph 3,
The memory controller compares the key versions of each of the second firmware image and the first firmware image when verification of the first certificate is completed,
Storage device. According to clause 5,
It further includes a ROM that stores the public key,
The memory controller verifies the second certificate using the public key stored in the ROM, and verifies the first certificate when verification of the second certificate is completed.
Storage device. According to clause 6,
The first certificate includes the signature of the first certificate, the second certificate includes the signature of the second certificate, and the signature of the first certificate and the signature of the second certificate are generated with the same private key. ,
Storage device. In clause 7,
The memory controller verifies the signature of the second certificate using the public key stored in the ROM,
Storage device. In clause 7,
The memory controller verifies the signature of the first certificate using the second certificate public key,
Storage device. multiple memory systems, and
Control the plurality of memory systems, receive a firmware image including firmware data and a firmware fingerprint from a host through a signal connector, and if the hash value of the firmware data and the firmware fingerprint do not match, the firmware image is A controller that reports to the host that it has been tampered with.
Contains a storage device.storage device.