ATSHA204A安全芯片：加密认证与数据保护

需积分: 5 164 浏览量更新于2024-06-26 收藏 1.28MB PDF 举报

"ATMEL-ATSHA204A.pdf 是Atmel公司出品的ATSHA204A原版英文手册，主要涉及加密解密技术。该芯片主要用于确保下载和启动的安全，验证代码身份，防止非法复制以及保护物联网节点的信息安全。" ATMEL ATSHA204A是一款专门设计用于安全认证的加密元件，它提供了硬件保护的密钥存储，以增强系统安全。这款设备的主要功能包括： 1. 安全下载和启动：ATSHA204A可确保代码在下载和执行过程中的安全性，防止未授权的修改或恶意代码注入。 2. 认证和保护代码：通过验证设备和网络节点的身份，保证只有原始制造商或授权的配件可以正常工作，防止克隆和非法复制。 3. 生态系统控制：确保只有经过OEM（原始设备制造商）或授权的节点和附件能够接入并操作，有助于维护一个安全可控的生态系统。 4. 抵抗克隆：通过独特的特性，如72位唯一的序列号，防止使用相同物料清单（BOM）或被盗代码建立完全相同的设备。 5. 消息安全：提供认证、消息完整性以及网络节点间信息的机密性，支持物联网（IoT）环境下的安全通信。 6. 加密认证：确保事物和代码的真实性、未篡改性和保密性，应用了优越的SHA-256哈希算法，支持消息认证码（MAC）和基于哈希的消息认证码（HMAC）选项。 7. 强大的密钥管理：拥有256位的业界最佳密钥长度，最多可存储16个密钥，增强了密钥的安全性。 8. 高质量随机数生成器（RNG）：提供内部的随机数生成，用于生成不可预测的密钥或初始化向量，增加系统的随机性和安全性。 9. 存储功能：包括4.5Kb的EEPROM用于存储密钥和数据，以及512位的一次编程（OTP）位，用于固定信息的写入。 10. 多种接口选择：支持UART兼容的高速单线接口和1MHz的I2C接口，适应不同应用场景的需求。 11. 电源电压范围宽：工作在2.0V至5.5V，通信电压则可从1.8V到5.5V，具有良好的电源适应性。综上，ATSHA204A是一款高效且全面的安全解决方案，广泛应用于物联网设备、智能硬件、安全认证等领域，确保了从设备身份验证到数据传输等各个环节的安全性。

ATSHA204A [DATASHEET]

Atmel-8885H-CryptoAuth-ATSHA204A-Datasheet_112015

2.1.2.15 Special Memory Values in the Configuration Zone (Bytes 0 – 12)

Various fixed information is included in the ATSHA204A that can never be written under any circumstances and

can always be read, regardless of the state of the lock bits.

 SerialNum

Nine bytes (SN[0:8]) which together form a unique value that is never repeated for any device in the

CryptoAuthentication family. The serial number is divided into two groups:

1. SN[0:1] and SN[8]

The values of these bits are fixed at manufacturing time in most versions of the ATSHA204A. Their

default value is (

0x01 0x23 0xEE). These 24 bits are always included in the SHA-256 computations

made by the ATSHA204A.

2. SN[2:7]

The values of these bits are programmed by Atmel during the manufacturing process and are

different for every die. These 6-bytes (48-bits) are optionally included in some SHA-256

computations made by the ATSHA204A.

 RevNum

4-bytes of information that are used by Atmel to provide manufacturing revision information. These bytes

can be freely read as RevNum[0:3], but should never be used by system software, because they may vary

from time to time.

2.1.3 One Time Programmable (OTP) Zone

The OTP zone of 64 bytes (512 bits) is part of the EEPROM array, and can be used for read-only storage.

Prior to locking the configuration section (using lockConfig), the OTP zone is inaccessible and can be neither

read nor written. After configuration locking, but prior to locking of the OTP zone (using lockData), the entire

OTP zone can be written using the Write command. If desired, the data to be written can be encrypted. When

unlocked the OTP zone cannot be read.

Once the OTP zone is locked, the OTPmode byte in the Configuration zone controls the permissions of this

zone, as follows:

 Read-only Mode

In this mode, the data cannot be modified, and would be used to store fixed model numbers, calibration

information, manufacturing history, and/or other data that should never change. The Write command will

always return an error and leave the memory unmodified.

All 64-bytes within the OTP section are always available for reading using either 4-byte or 32-byte reads.

 Consumption Mode

In this mode, the bits function as one-way fuses, and can be used to track consumption or usage of the

item to which the ATSHA204A is attached. For examples, in a battery, they might be used to track

charging cycles or use time; in a printer ink cartridge, they might track the quantity of material consumed;

in a medical device, they might track the number of permitted uses for a limited use item.

In this mode, the Write command can only cause bits to transition from a one to a zero. Logically, this

means the data value in the input parameter list will be AND'ed with the current value in the word(s) and

the result written back to memory.

Example: Writing a value of 0xFF results in no change to the byte and writing a value of 0x00 causes the

byte in memory to go to zero, regardless of the previous value. Once a bit has transitioned to a

zero, it can never transition back to a one.

ATSHA204A [DATASHEET]

Atmel-8885H-CryptoAuth-ATSHA204A-Datasheet_112015

2.1.4 Device Locking

There are two separate lock bytes for the device:

 Lock the Configuration zone (controlled by LockConfig, byte 87).

 Lock both the Data and OTP zones (controlled by LockData, byte 86).

These locks are stored within separate bytes in the Configuration zone, and can be modified only through the

Lock command. After a memory zone is locked, there is no way to unlock it.

The device should be personalized at the system manufacturer with the desired configuration information, and

the Configuration zone should be locked. When this lock is complete, all necessary writes of public and secret

information into the EEPROM slots should be performed using encrypted writes if appropriate. Upon completion

of writes to the data and OTP zones, the Data and OTP zones should be locked.

It is vital that the Data and OTP zones are locked prior to release of the system containing the device into the

field. Failure to lock these zones may permit modification of any secret keys and may lead to other security

problems.

Any attempt to read or write the Data or OTP sections prior to locking the configuration section causes the

device to return an error.

Contact Atmel for optional secure personalization services.

2.1.4.1 Configuration Zone Locking

Certain bytes within the Configuration zone cannot be modified, regardless of the state of LockConfig. Access to

the remainder of the bytes within the zone is controlled using the LockConfig byte in the Configuration zone, as

shown in Table 2-7. Throughout this document, if LockConfig is 0x55, then the Configuration zone is said to be

unlocked; otherwise it is locked.

Table 2-7. Configuration Zone Locking

2.1.4.2 Data and OTP Zone Locking

Throughout this document, if LockData is 0x55, then both the Data and OTP zones are said to be unlocked;

otherwise they are locked.

Note: There is neither read nor write access to the Data and OTP zones prior to locking of the Configuration

zone.

Table 2-8. Data and OTP Zone Access Restrictions

Note: 1. Based on Slot Configuration for a given slot.

2.1.4.3 OTP Zone Locking

Reads and writes of the OTP zone depend upon the state of the LockConfig, LockData, and OTP mode bytes in

the Configuration zone.

Read Access Write Access

LockConfig == 0x55 (unlocked) Read Write

LockConfig != 0x55 (locked) Read <never>

Read Access Write Access

LockData == 0x55 (unlocked) <never> Write

LockData!= 0x55 (locked) Read

(1)

Write

(1)

ATSHA204A [DATASHEET]

Atmel-8885H-CryptoAuth-ATSHA204A-Datasheet_112015

2.2 Static RAM (SRAM)

The device includes an SRAM Array that is used to store the input command or output result, intermediate

computation values, and/or an ephemeral key. The entire contents of this memory are always invalidated

whenever the device goes into sleep mode or the power is removed. The ephemeral key is named TempKey,

and can be used as an input to the MAC, HMAC, CheckMac, GenDig, and DeriveKey commands. It is also

used as the Data protection (Encryption or Decryption) key by the Read and Write commands. See the

below, Section 2.2.1, “TempKey”.

2.2.1 TempKey

TempKey is a storage register in the SRAM array that can be used to store an ephemeral result value from the

Nonce, GenDig, CheckMac, or SHA commands. The contents of this register can never be read from the

device (although the device itself can read and use the contents internally).

This register contains the elements shown in Table 2-9.

Table 2-9. TempKey Storage Register

In this specification, the name “TempKey” refers to the contents of the 32-byte (256-bit) Data register. The

remaining bit fields are referred to as TempKey.SourceFlag, TempKey.GenData, and so on.

The TempKey.Valid bit is cleared to zero under any of the following circumstances:

 Power-up, sleep, brown-out, watchdog expiration, or tamper detection. The contents of TempKey are

however retained when the device enters idle mode.

 After the execution of any command other than Nonce or GenDig, regardless of whether or not the

command execution succeeds. It may be cleared by the CheckMac command unless a successful copy

takes place. It is not cleared if there is a communications problem, as evidenced by a Cyclic Redundancy

Check (CRC) error.

 An error during the parsing or execution of a GenDig and/or Nonce command.

 Execution of GenDig replaces any previous output of the Nonce command with the output of the

GenDig command. Execution of the Nonce command likewise replaces any previous output of the

GenDig command.

Name Bit Length Description

TempKey

256

(32-bytes)

Nonce (from Nonce command) or Digest (from GenDig command).

SlotID 4

If TempKey was generated by GenDig (see the GenData and CheckFlag bits), these bits

indicate which key was used in its computation. The four bits represent one of the slots of

the Data zone.

SourceFlag 1

The source of the randomness in TempKey:

0 = Internally generated random number (Rand).

1 = Input seed only, no internal random generation (Input).

GenData 1

0 = TempKey.SlotID is not meaningful, and is ignored.

1 = The contents of TempKey were generated by

GenDig using one of the slots in the

Data zone (and TempKey.SlotID will be meaningful).

CheckFlag 1

If one, the contents of TempKey were generated by the GenDig command and at least

one of the keys used in that generation is restricted to the

CheckMac command

(SlotConfig.CheckOnly is one); otherwise, this bit will be zero.

Valid 1

0 = The information in TempKey is invalid.

1 = The information in TempKey is valid.

剩余81页未读，继续阅读

huabutterfly

粉丝: 0
资源: 5

ATSHA204A安全芯片：加密认证与数据保护

ATSHA204A.pdf

Atmel ATSHA204A Datasheet

Atmel-8885-CryptoAuth-ATSHA204A-Datasheet.pdf

atsha204a初始化

atsha204a keil例子

设备树中添加基于i2c的ATSHA204A加密芯片

atsha204a官方库源码

atsha204a c 语言实现

ATSHA204A-SSHDA

atsha204a初始化代码

最新资源