cryptography and the smart grid ppt

An Introduction to Cryptography as Applied to the Smart GridJacques Benoit, Cooper Power Systems

Western Power Delivery Automation ConferenceSpokane, WashingtonMarch 2011

Agenda

> Introduction> Symmetric Cryptography> Message Integrity and Authentication> The IEC 62351 Standards> DNP3 Secure Authentication> Asymmetric Cryptography> Digital Signatures> Certificates and Certificate Authorities> Transport Layer Security> Conclusion

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Introduction

> Cryptography is the practice and study of hiding information.> Origins date more than 2000 years ago.> Takes it root in the Greek word kryptos, meaning hidden.> The National Institute of Science and Technology (NIST) plays

a major role in defining cryptographic standards.> NIST published first encryption algorithm for general use in

1974.> Cryptography provides a set of tool to meet information security

requirements: Confidentiality Authentication Integrity Non-repudiation

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Symmetric Cryptography

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ALICE BOB

Symmetric Cryptography Standards

> 1977 – Data Encryption Standard (DES) adopted as FIPS 46 federal standard for unclassified data. 56-bit key

> 1999 – FIPS 46-3 standard recommends the use of Triple DES (TDES or 3DES) for increased security. With 2 keys, effective strength of 80 bits With 3 keys, effective strength of 112 bits and approved for

use until 2029> 2001 – FIPS 197 Advanced Encryption Standard (AES)

128, 192, or 256 bit keys 128 bit key is approved for use beyond 2030

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Message Integrity

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Message Authentication Code(MAC)

Message Authentication Codes

> Checksums and Cyclic Redundancy Check (CRC) designed to detect common communications errors.

> Fast. But not designed to provide security. Easy to generate two messages with same value.

> Cryptographic hashes are slower, but it is extremely difficult to generate two messages with same hash.

> MD5 (Message-Digest algorithm 5) is widely used and generates a 128 bit digest. It is no longer considered secure.

> SHA-1 replaced MD5 and produces a 160 bit digest. Weaknesses have been identified.

> SHA-2 defines four functions to replace SHA-1: SHA-224, SHA-256, SHA-384 and SHA-512.

> SHA-224 is approved for use until 2029.> SHA-3 is under development.

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Message Integrity and Authentication

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Hashed-based Message Authentication Code

(HMAC)

Hash-based Message Authentication Code (HMAC)

> Hash-based Message Authentication Code (HMAC) algorithm uses the key as part of the hashing process.

> HMAC algorithm is designed to be used with any hash function.

> SHA-1 with key greater than 112 bits, but shorter that 128 bits is acceptable until 2030.

> After 2030, key should have more than 128 bits.

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IEC 62351 Information Security for Power System Control Operations

> IEC 62351 was developed for handling the security of TC-57 protocols including IEC 61850, IEC 60870-5 and it derivatives, such as DNP3 IEC 62351-3 specifies how to secure TCP/IP-

based protocols through the use of Transport Layer Security (TLS).

IEC 62351-5 specifies how to add user and device authentication, and data integrity.

> The DNP3 Secure Authentication extension was designed to meet the requirements of IEC 62351-5

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DNP3 Secure AuthenticationInitial Handshake

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DNP3 Secure AuthenticationChallenge-Response

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Solving the Key Management Challenge:Asymmetric Cryptography

> In symmetric cryptography both parties share a secret key used to encrypt and decrypt messages.

> In asymmetric cryptography, keys come in pairs.> A message encrypted with one key can only be decrypted

using the other key.> One key is known as the public key and can be widely shared. > The other key, known as the private key, is kept in a secure

location. > The sender of a message can use the intended receiver’s

public key to encrypt the message. > Only the intended receiver with the appropriate private key will

then be able to decrypt the message.

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Asymmetric Cryptography

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ALICE BOB

Digital Signatures

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ALICE BOB

Public Key Certificates

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Approved Asymmetric Algorithms

> Approved algorithms are: Rivest, Shamir and Adleman (RSA) with 2048

bits until 2029, RSA with 3072 bits, for CAs after 2030. Elliptic Curve Cryptography (ECC) with curves P-

224, K-233, or B-233 until 2029 until 2029. ECC with curves P-256, P-384, P-521, K-283, K-

409, K-571, B-283, B-409 and B-571 after 2030.

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Certificates and the Smart Grid

Certificates are widely used in a variety of protocols and technologies:> ZigBee Smart Energy devices> 802.1x port-based access control for WLANs> Internet Protocol Security (IPsec) protocol suite> Transport Layer Security (TLS) protocol> S/MIME (Secure/Multipurpose Internet Mail

Extensions) and PKCS#7 for secure email and signed software updates

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Transport Layer Security (TLS)

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Conclusion

> Cryptography is a hidden component in many of the technologies of the Smart Grid

> It provides confidentiality, authentication and integrity for data exchanges

> NIST has been mandated to recommend standards and a security model for the Smart Grid.

> NIST has submitted five “foundational” family of standards to FERC

> FERC will introduce regulation when there is sufficient consensus

> IEC 62351 is one of the recommended standards

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Contact Information

Jacques BenoitSenior Analyst Information Security

Cooper Power SystemsJacques.Benoit@CooperIndustries.com

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