cryptoauthentication ™ real. easy

1 © 2014 Atmel Confidential CryptoAuthentication™ 2014

CryptoAuthentication™ Real. Easy.


• Cryptography Introduction• Use Cases for Hardware Security Devices

• Authentication, Trusted Identification, Secure boot, Download Protection, Anti-cloning, Consumption tracking, and more

• Crypto Authentication Product Portfolio• ATSHA204(A)• ATAES132• ATECC108(A)

• FIPS certified Embedded Systems• Trusted Platform Module

Agenda


Does Security Matter?

What Happened?• Hackers loaded unauthorized code

into system• Common system architecture to

store program in Flash and let users download updated versions from the web

How Can Atmel Help?• Put ATSHA204 in system to

enable firmware validation capability upon any software download or update event



What Happened?• Hackers exploited bug in

crypto code• Hard for every system

designer to be a cryptographic expert, open-source crypto code may be imperfect

How Can Atmel Help?Add ATSHA204 for:• Secure key storage• Hardware

implementation of algorithm

• Random number generator


Concepts of CryptographicAlgorithms


Encryption vs. Authentication

EncryptText Decrypt Text

Text VerifySign

Cipher Text

Signature

Text

Authentication

Encryption

Only Receiver can see the text in the clear

Receiver can determine identity of sender,make sure text wasn’t changed


Hashing vs. Encryption

• Data can be scrambled and unscrambled• Provides confidentiality so that data can only be

understood by authorized users

• Common algorithms: AES, DES, RSA, ECC

• Data is scrambled/compressed into a fixed length digest• Constant input always generates the same digest• Can be used to verify the identity of the sender • Can verify the integrity of the message - that it hasn’t

been changed

• Usually SHA, but AES can be used as a hash algorithm

Encryption(2 Way)

Hash(1 Way)


M Challenge

System B

KEYSECRET

SHA256

Response

System B Compares the Hash of M with

the Response to verify the shared

Secret

Symmetric Authentication

• Notice System A and System B MUST Share Knowledge of a Secret Key• All Systems with Secret Key can create and verify

System A

KEYSECRET

SHA256


KEYPRIVATE

SignM Verify

KEYPUBLIC

Signature

Verifies Message with the

Signature and Public Key of the

Signer

Message

Asymmetric Authentication

• The Signer has a unique Private Key• Only the System with the Private Key can Sign the message• All Systems can verify the signature• Verify uses only public data

1. Message to Sign2. Signature generated by the private key3. Public Key associated with the private key


Hardware Security System Use Cases


• Authentication• Mobile devices: Chargers, batteries, adapters, speakers,

keyboards, etc.• Industrial devices: Sensors

• IP Protection• Prevent copying/cloning of system and software, authenticate

phone/tablet software to OEM hardware, manage licensing revenue

• Secure Communication• Wireless Systems, Wired Systems (PLC, Ethernet, ...),

• Trusted Operation• Secure boot to ensure that system works as desired – medical,

industrial, metering• Encrypted downloads: ensure OEM approved software

CryptoAuthentication


Symmetric* Authentication Example Symmetric Authentication occurs when host verifies that its key and the

client’s key match.

MCU

Not Verified

Verified

Response

Challenge SecureStorageSecureStorage

Host Client

HASH Function

(SHA)

HASH Function

(SHA)HASH VALUE

(Digest)

HASH VALUE

(Digest)

=?

Random Number

*With symmetric authentication the host and client always have the same secret key.

Verify


The authentication of ECC108 is done in two phases

First Phase: Verify Certificate Signature• Is the device certificate signed by my trusted certificate chain?• Perform ECDSA verify (signer public key, signature, digest of cert)

After First Phase, you can trust the device public key

Second Phase: Verify Private Key• Send random message to be signed by the device private key• Perform ECDSA verify (device public key, signature, random message)

Asymmetric Authentication Phases


Host requests & receives certificate from client

Host extracts signature, client’s public key, & certificate data. Then hashes certificate data to create a digest.

Host runs ECDSA Verify Calculation on its public key, digest & client’s signature. If it succeeds then client’s public key is verified, and can go to phase 2.


+

Host PublicKey

Digest Function

Verify Public Key

Certificate Data

Phase 1


Host creates random number challengeHost sends challenge to client.Client uses ECDSA engine to sign random number with client’s

private key.Client sends signature to host

Host runs ECDSA Verify using client public key verified in phase 1, random number, & new signature from client. If it succeeds then the Private Key is verified.


ATECC108

Verify Private Key

Phase 2



HostMCU

Accessory (Client)ATECC108

Random Number

Generator

ECDSASignature

Engine

Fail Success

Challenge

Signature

RandomChallenge

ECDSAVerify

Calculation

Host Public Key

Fail Success

ECDSAVerify

Calculation

AccessoryCertificate

Digest Function

Signature

Client Public Key

The two phases of ECDSA put together

Certificate Data

ClientPrivate

Key

Client PublicKey

Verify Public Key

Verify Private Key


User Identity – Validate that a user is who he says he is without having to reveal the user’s secret. Authenticate serial numbers

Sensor Location – Identify which sensor, where it’s located, validate source of the control message

Data Integrity – Verify that the message (file/packet/data) hasn’t been compromised when in transit/storage

Consumables – Maintain OEM revenue flow (razor/razor blade business model). Ensure that device are not used beyond their

expected life

Spare Parts – Verify only factory genuine parts are used

Authentication Can Mean Many Things


Secure CommunicationSecure Session Key Generation

●Session Key Generation for Symmetric-key Based Systems●Tamper-resistant Hardware Security IC Provides Root of

Trust●Achieve Both Machine Authentication and Secure

Communications


Firmware IP protection - Method of Protection

· Concept: Software Communicates with Security Device· Send challenge message to security chip, check response for

correctness· Only systems with properly programmed security devices will

work correctly

· Goal: Increase Cost of Attack!· If properly implemented, each check in the code must be

found and removed separately· Require a new and separate attack with each revision of

program


Security Devices Can Help Prevent Piracy

• Software communicates with security device• Send challenge message to security chip, check

response for correctness• Only system with properly programmed security device

will work correctly• Multiple checks in software

• 10, 100, 1000 – as many as are practical• Different values for each check

• Be creative!• Use diverse methods to send challenge and deal with

response• Some methods should include fixed challenge-

responses, some should include random challenges and compiled in keys

• Change methods with each software update• Use all key slots, check different set of slots with each

version


Simple Example

// 0x1234 is challenge to ATSHA204*// 0xABCD is correct response from ATSHA204. . .if (sendChallenge(Slot0, 0x1234) != 0xABCD){ error(“System Fault”); exit(-1); }

. . .

ATSHA204 in every system has same secret in Slot0

Practically infinite number of possible challenges Only one correct response for each challenge

Each system could optionally have unique challenge-response pairs compiled in

This code construct may be easy to find and remove via reverse compilation

*These examples show the challenge and response as a 16 bit integer for clarity and simplicity. They will actually be 32 byte arrays for

ATSHA204.

23 © 2014 Atmel Confidential CryptoAuthentication™ 2014 03/14/2012Select Insert > Header & Footer > Type Title in Footer field

CLIENTMICRO

=?

Authentication VerifiedYes

Response

Challengead00 10e0 d467 25de 8c60 8f60 5b93 5f7e 2354 a436 cb44 1486 f18d 03b2 d911 81cf

ad00 10e0 d467 25de 8c60 8f60 5b93 5f7e 2354 a436 cb44 1486 f18d 03b2 d911 81cf

0100011001011110000011110100010110010111001111110101010010111110000111110010

ad00 10e0 d467 25de 8c60 8f60 5b93 5f7e 2354 a436 cb44 1486 f18d 03b2 d911 81cf

SHA256Secret Key

ATSHA204

RESPONSE

CHALLENGE

Anti-Piracy Example Technique using • Fixed Challenge Response

• But what if the authentication verification answer is no?

68b1 282b 91de 2c05 4c36 629c b8dd 447f 12f0 96d3 e3c5 8797 8dc2 2484 4463 3483

68b1 282b 91de 2c05 4c36 629c b8dd 447f 12f0 96d3 e3c5 8797 8dc2 2484 4463 3483


Slightly More Complicated Example// 0x1234 is challenge to ATSHA204// 0xABCD is correct response from ATSHA204. . .int resp, chal = 0x1200;

chal += 0x0034;resp = sendChallenge(Slot0, chal);answer += resp;answer -= 0xABCD;. . .

Vary the constructs

Use state variables as the challenge Use responses as part of calculation, jump vector, etc.

An attacker with a logic analyzer on the bus may be able to record all the correct responses


Microcontroller ATSHA204Secure

KeyStorage

SHA-256Hash

Engine

Do TheyMatch ? No Yes

Challenge

Response

Challenges Compiled

into Software

Intermediate KeysCompiled

into SoftwareDate, Time, RNG, etc.

SHA-256Hash

EngineSHA-256SW

UniqueNonce

Even More Complicated Example

IntermediateKeys

Can’t be attacked with a logic analyzer


Measures that could be taken if the system fails the validation process

Send Error messageBlacklist a deviceMake a device in-operableHave code do something unexpected or incorrect (ex. Cell phone always dials wrong numbers) Limit/Reduce functionality of deviceDisplay message stating that the required (legitimate) software must be downloadedSome other creative idea


No Limits to Programmer’s Creativity!

• Multiple checks in software, each different• 10, 100, 1000 – as many as are practical

• Change methods with each software update• Program multiple slots, each version works differently

• Use all the key slots & methods• Vary the slots used with date, revision number

• Make sure that some methods require runtime analysis• Chain or combine one response as the next challenge• Use response as part of a jump vector or table pointer

• Consider web-based system enablement• Server can use ATSHA204 dongle for secure checks

• ATSHA204 includes password handler• May provide useful capability in some situations

• Maintain blacklist of invalid serial numbers• Can be updated with software revisions

and so on…


None

MU

MU + CC

FC

MU + CC + PA + CM

MU + CC + PA + CM + DC

CC + PA + CM + DC + RC

CC + PA + CM + DC + RC + TK

CC + PA + CM + DC + RC + TK + RK

IncreasedProtection

Increase the Complexity

RK = Rolled KeyTK= Move the Challenge to Temp

KeyRC= Random Challenge

ResponseDC = Dynamic

Challenge on the StackCM = Code

MisdirectionPA= Periodic AuthenticationsCC= Chaining Challenge

ResponsesMU = Multiple

Unordered Fixed Chall/RespFC = Fixed Challenge

Response


CryptoAuthenticationproducts


MultipleSerial I/O options

SecuredEEPROM

ECC / SHA /AES Cryptographic

Engine

Monotonic Counters

High Quality Random Number

Generator

Unique Serial Number

Tamper-hardened Hardware Boundary

Optimized for high security, ease-of-use and low costCrypto Architecture

Attackers cannot see what’s inside

Standards based crypto engine

between interface and memory

Isolates any attack to a

single device

I/O options simplify

design in

Tracks number of

authentications

Required for every crypto

protocol

Secured EEPROM for keys & data


Hardware Security Features• Strong Multi-Level HW Security:

• Active shield over entire chip• All memories internally encrypted• Data independent crypto execution• Randomized math operations• Internal state consistency checking• Voltage tampers, isolated power rail• Internal clock generation• Secure test methods, no JTAG• No debug probe points, no test pads• No package or die identification

• Designed to Defend Against:• Microprobe attacks• Timing attacks• Emissions attacks• Faults, invalid command attacks• Power cycling, clock glitches• Partial personalization attacks

StandardDevices

ATMEL CryptoAuthentication

Cannot achieve this level of security with software alone!


• ATSHA204• Standard SHA256 hash algorithm• Secure key storage (16 slots)• Turnkey authentication, validation, key derivation, password checking• Functionality for both Host and Client configurations

• ATECC108• Full 256-bit Elliptic Curve Cryptography (ECC)• No requirement for secure storage in the host system• Fast execution reduces code and performance requirements• Complete compatibility with ATSHA204

• ATAES132• Secure storage for both data (32Kb) and keys (16 slots)• Rich command set to support every system architecture• Drop-in compatibility with industry standard 32Kb Serial EEPROM

High Level Device ComparisonWorld Class Hardware Security to Complement Every Micro


Where to Use ATECC108, ATSHA204 or ATAES132

• Customers Who Are Most Price Sensitive – Use ATSHA204

• Host hardware cannot be easily changed – Use ATECC108

• Compatibility with Serial EEPROM is a benefit• All Three Parts use same packages & pinout when configured for I2C• Systems that need full software compatibility or SPI – Use ATAES132

• All components of system come from same OEM – Use ATSHA204

• Systems w/many partners, complex ecosystem – Use ATECC108

• Need to Secure up to 4Kbytes of data for Fingerprints, Calibration data, Firmware blocks, etc.. – Use ATAES132


Standards-Based Security

Targeting OS-Based Embedded Systems


What is a TPM?

TPM is a Hardware-based Key Storage device providing a “Secure Vault” for any Embedded System

• Four Primary Capabilities• Platform Integrity• Authentication• Secure Communication• IP Protection

• Asymmetric Algorithm (RSA)• Supports 512, 1024, & 2048 keys• SHA-1 Hashing & HMAC

• Industry Standard Specification• Trusted Computing Group• In every commercial PC, most servers


TPM … Way Beyond PCs

• Anything on a network!• LTE base stations• Servers• Multifunction printers• Gambling / gaming machines• Access points• Smart appliances with network

connectivity• Test & measurement devices• Mobile payment terminals• Inventory control terminals

http://www.wms.com/games_mechanical.php


Support Tools


ACES Demonstration/Evaluation Software

www.atmel.com/cryptokits

• ACES• Demo• Evaluate• Educate• Design

• A platform to exercise CryptoAuthentication devices

• Demos & Wizards to visualize end uses

• Learn the memory and commands of CryptoAuthentication devices

• See properly formatted commands for firmware

• Stores and reloads configurations

• Works with any CryptoAuthentication kit

http://www.atmel.com/cryptokits


• www.atmel.com• Stand alone Library for Atmel CryptoAuthentication Devices

• ATSHA204• http://www.atmel.com/tools/CRYPTOAUTHENTICATIONATSHA204DEVE

LOPMENTLIBRARY.aspx• ATECC108

• http://www.atmel.com/tools/CryptoAuthentication_ATECC108_Development_Library.aspx

• ATAES132• http://www.atmel.com/tools/CRYPTOAUTHENTICATIONATAES132DEVE

LOPMENTLIBRARY.aspx

CryptoAuthentication Tools and Support

http://www.atmel.com/

http://www.atmel.com/tools/CRYPTOAUTHENTICATIONATSHA204DEVELOPMENTLIBRARY.aspx

http://www.atmel.com/tools/CRYPTOAUTHENTICATIONATSHA204DEVELOPMENTLIBRARY.aspx

http://www.atmel.com/tools/CryptoAuthentication_ATECC108_Development_Library.aspx



http://www.atmel.com/tools/CRYPTOAUTHENTICATIONATAES132DEVELOPMENTLIBRARY.aspx

http://www.atmel.com/tools/CRYPTOAUTHENTICATIONATAES132DEVELOPMENTLIBRARY.aspx


Logic Analyzer

• Saleae• Low cost Logic Analyzer with support for both I2C and Atmel’s Signal Wire

Interface (SWI)• App note available at:http://www.atmel.com/Images/Atmel-8847-CryptoAuth-ATSHA204-SWI-I2C-Debugging-Saleae-Logic-Analyzer-ApplicationNote.pdf

Built In Atmel Protocol Analyzer

http://www.saleae.com/logic16?gclid=CPGSzYWO0boCFc-Y4Aod-3UArg

http://www.atmel.com/Images/Atmel-8847-CryptoAuth-ATSHA204-SWI-I2C-Debugging-Saleae-Logic-Analyzer-ApplicationNote.pdf

http://www.atmel.com/Images/Atmel-8847-CryptoAuth-ATSHA204-SWI-I2C-Debugging-Saleae-Logic-Analyzer-ApplicationNote.pdf


• Application Notes• ATSHA204 Authentication Modes

• ATSHA204 Single-Wire and I2C Seamless Debugging Using Saleae Logic Analyzer

• Secure Session Encryption Key Exchange with ATSHA204

• Secure Boot Simplified

• Designing with CryptoAuthentication Client Devices

• Application Brief: Analyzing Strength of Security

CryptoAuthentication Tools and Support

• The ATECC108 supports all the functionality of the ATSHA204


AT88CK490 CryptoAuthentication Demonstration & Evaluation Kit

ATSHA204ATECC108ATAES132

Software: Atmel Crypto Evaluation Studio (ACES)


• Development Tools Reduce Time to Market• Easily connect to any AVR or

ARM development platform• 100% support for Atmel MCUs

and development kits• Complete Development

Environment• Source code libraries and

example code available for free at www.atmel.com/cryptokits

• Libraries fully tested for AVR micros

• ACES Software Exploration tool• Ordering Codes based on

package type

Evaluate and Develop with AT88CK101STK

AT88CK101- ()CryptoAuthentication Development Kit

* AT88CK101STK8-MAH (UDFN) shown

http://www.atmel.com/cryptokits


• Start sending commands to the TPM immediately

• Includes… • TPM SMBus Module• Mounted on AT90USBKey Board• Standard A to Mini B USB device

cable• Mini A to receptacle A USB host

adapter• USB flash drive• Alternate 9V battery supply cable

Introducing Atmel’sEmbedded TPM

Starter Kit!

Flash Drive includes Sample Code & All Necessary Documentation!


• The AT88CK9000 Board is design for stand-alone secure programming of CryptoAuthentication family.

• The board support a XML configuration file generated by ACES and is securely stored within the programmer board.

• For large annual volumes, contact Atmel for other solutions.

• Ordering Codes based on package type

CryptoAuthentication Low Volume Personalization

AT88CK9000-xxx


© 2014 Atmel Corporation. All rights reserved.

Atmel®, Atmel logo and combinations thereof, Enabling Unlimited Possibilities®, and others are registered trademarks or trademarks of Atmel Corporation or its subsidiaries. Other terms and product names may be trademarks of others.

Disclaimer: The information in this document is provided in connection with Atmel products. No license, express or implied, by estoppel or otherwise, to any intellectual property right is granted by this document or in connection with the sale of Atmel products. EXCEPT AS SET FORTH IN THE ATMEL TERMS AND CONDITIONS OF SALES LOCATED ON THE ATMEL WEBSITE, ATMEL ASSUMES NO LIABILITY WHATSOEVER AND DISCLAIMS ANY EXPRESS, IMPLIED OR STATUTORY WARRANTY RELATING TO ITS PRODUCTS INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT. IN NO EVENT SHALL ATMEL BE LIABLE FOR ANY DIRECT, INDIRECT, CONSEQUENTIAL, PUNITIVE, SPECIAL OR INCIDENTAL DAMAGES (INCLUDING, WITHOUT LIMITATION, DAMAGES FOR LOSS AND PROFITS, BUSINESS INTERRUPTION, OR LOSS OF INFORMATION) ARISING OUT OF THE USE OR INABILITY TO USE THIS DOCUMENT, EVEN IF ATMEL HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. Atmel makes no representations or warranties with respect to the accuracy or completeness of the contents of this document and reserves the right to make changes to specifications and products descriptions at any time without notice. Atmel does not make any commitment to update the information contained herein. Unless specifically provided otherwise, Atmel products are not suitable for, and shall not be used in, automotive applications. Atmel products are not intended, authorized, or warranted for use as components in applications intended to support or sustain life.

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