(AMD) Codes from Linear Codes and their Application to Storage

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On AMD Codes for Storage Systems. ITW 2015 ... This presentation is on privacy and security aspects of distributed ... Security and Integrity in Storage Networks.
Introduction

AMD codes

Our contributions

Discussion

On Algebraic Manipulation Detection (AMD) Codes from Linear Codes and their Application to Storage Systems J. Harshan and Fr´ed´erique Oggier Division of Mathematical Sciences, Nanyang Technological University, Singapore

Supported by the MoE Tier-2 grant “eCode: erasure codes for data center environments”

Oct. 2015 1/13 On AMD Codes for Storage Systems

ITW 2015

Introduction

AMD codes

Our contributions

Discussion

So far...

This presentation is on privacy and security aspects of distributed storage 2/13 On AMD Codes for Storage Systems

ITW 2015

Introduction

AMD codes

Our contributions

Discussion

Security and Integrity in Storage Networks

The model is such that message stored is private and cannot be seen by adversary, but adversary can manipulate the stored messages using a priori information. On AMD Codes for Storage Systems

3/13 ITW 2015

Introduction

AMD codes

Our contributions

Discussion

Security and Integrity in Storage Networks

Error control codes (K.V Rashmi et al. 2012), Hash functions (F. Oggier and A. Datta 2011, Y.S. Han et al. 2011), Message authentication codes (Chen and Lee, 2013)

4/13 On AMD Codes for Storage Systems

ITW 2015

Introduction

AMD codes

Our contributions

Discussion

Highlights of our work ◮





We apply AMD codes to distributed storage ◮

Information theoretic security approach



Low storage overhead

We have developed on the work of ◮

E. Jongsma, Algebraic Manipulation Detection Codes, 2008



R. Cramer et al. Detection of Algebraic Manipulation with Applications to Robust Secret Sharing and Fuzzy Extractors, 2008

We provide new insights on construction of AMD codes 5/13

On AMD Codes for Storage Systems

ITW 2015

Introduction

AMD codes

Our contributions

Discussion

AMD Codes

6/13 On AMD Codes for Storage Systems

ITW 2015

Introduction

AMD codes

Our contributions

Discussion

AMD codes from Linear Codes (E. Jongsma, 2008) A (q m , N q m+1 )-AMD code from a linear (N, m) code over Fq E : Fm → Fm q q × ZN × Fq , v 7→ (v, i, [vG]i ) where G is the generator matrix of the linear code. Manipulation E(v) + δ = (v, i, f (i, v)) + (∆(v), g1 , g2 ) = (v + ∆(v), i + g1 , f (i, v) + g2 ). Deception Event D(E(v) + δ) = D(E(v′ )) = v′ for v′ 6= v On AMD Codes for Storage Systems

7/13 ITW 2015

Introduction

AMD codes

Our contributions

Discussion

A Relevant Metric (E. Jongsma, 2008) µ(S) = max max |{i, (c − c′ )i = a}| ′ c6=c ∈S a∈Fq

8/13 On AMD Codes for Storage Systems

ITW 2015

Introduction

AMD codes

Our contributions

Discussion

Performance of AMD codes

Theorem (E. Jongsma, 2008) A (q m , N q m+1 )-AMD code E is ǫ-secure for ǫ=

µ(cl(C)) where cl(C) := ∪t∈ZN rott (C) N

if for all t ∈ ZN , t 6= 0, rott (C) ∩ C = 0, and ǫ = 1 otherwise.

9/13 On AMD Codes for Storage Systems

ITW 2015

Introduction

AMD codes

Our contributions

Discussion

Preliminary Results Rate of the linear code

Lemma 1 m ≤ . N 2

Lower bound on µ(cl(C))

Lemma µ(cl(C)) ≥ 2m. 10/13 On AMD Codes for Storage Systems

ITW 2015

Introduction

AMD codes

Our contributions

Discussion

Example code for m = 2 Parameters: N = 16, q = 17 E : F217 7→ F217 × Z16 × F17 , v 7→ (v, i, [vG]i ).

G=



16 8 2 15 4 1 4 11 4 10 12 6 11 15 13 1 10 4 5 1 8 15 2 8 7 1 6 1 6 4 15 6



Properties ◮

The parameter µ(cl(C)) = 7 ≥ 4, 11/13

On AMD Codes for Storage Systems

ITW 2015

Introduction

AMD codes

Our contributions

Discussion

New Results Theorem A (q m , N q m+1 )-AMD code is ǫ-secure for ǫ=

µ(C) 1 + m N q

Theorem The code C generated by G has µ(C) =  m if and only if any ˜ = G , is full rank. (m + 1) × (m + 1) submatrix of G 1 12/13 On AMD Codes for Storage Systems

ITW 2015

Introduction

AMD codes

Our contributions

Discussion

Future Work



Improved bounds on the probability of deception



Connection to erasure codes from Vandermonde matrices



Implementation aspects



Relevant to other applications such as robust secret sharing schemes and fuzzy extractors.

13/13 On AMD Codes for Storage Systems

ITW 2015