Entangled Polynomial Codes for Secure, Private, and Batch Distributed Matrix Multiplication: Breaking the "Cubic" Barrier
QIAN YU (USC)
joint work with Salman Avestimehr (USC) IEEE International Symposium on Information Theory (ISIT) July 2020
Entangled Polynomial Codes for Secure, Private, and Batch - - PowerPoint PPT Presentation
Entangled Polynomial Codes for Secure, Private, and Batch Distributed Matrix Multiplication: Breaking the "Cubic" Barrier QIAN YU (USC) joint work with Salman Avestimehr (USC) IEEE International Symposium on Information Theory (ISIT)
joint work with Salman Avestimehr (USC) IEEE International Symposium on Information Theory (ISIT) July 2020
Qian Yu - Entangled Polynomial Codes (ISIT) July 2020
adversaries stragglers colluding workers "The Tail at Scale" Google, 2013
Qian Yu - Entangled Polynomial Codes (ISIT) July 2020
f( ) f( )
Problem Parameters
f( )
N workers
Coded Computing Yu et al, NIPS 2017 Goal: minimize recovery threshold given N,g,f
Design Space
Recovery Threshold: # workers’ results needed for recovering final outputs (equivalent to straggler resiliency and computation security)
Qian Yu - Entangled Polynomial Codes (ISIT) July 2020 Computation f - Channel Coded variables – Coded symbols Worker – Channel usage Recovery threshold – Communication rate (tolerate errors) Coded Computing vs Classical Shannon Theory
Key Challenge: how to design codes so that
Require New coding ideas! Differences:
combinatorial
Linear codes as a natural assumption
Qian Yu - Entangled Polynomial Codes (ISIT) July 2020
Yu et al, NIPS 2017
Qian Yu - Entangled Polynomial Codes (ISIT) July 2020
Yu et al, NIPS 2017
𝒏 submatrices 𝒐 submatrices
pair-wise products Ai
TBj
Requires 𝒏𝒐 workers
Qian Yu - Entangled Polynomial Codes (ISIT) July 2020
Yu et al, NIPS 2017
pair-wise products Ai
TBj
Requires 𝒏𝒐 workers
Encoding: worker i obtains 𝑏 𝑗 , 𝑐(𝑗) Worker i essentially calculates:
Recovery threshold = 𝒏𝒐
Qian Yu - Entangled Polynomial Codes (ISIT) July 2020
Recovery threshold Recovery threshold Recovery threshold
Qian Yu, Mohammad Ali Maddah-Ali, Salman Avestimehr, “Straggler Mitigation in Distributed Matrix Multiplication: Fundamental Limits and Optimal Coding”, Jan 2018, ISIT, TIT.
A better design for straggler mitigation (Entangled polynomial codes) Orderwise improvement for Secure, Private, Batch Matrix Multiplication
Qian Yu - Entangled Polynomial Codes (ISIT) July 2020
Qian Yu (USC)
p × 𝑛 blocks p × 𝑜 blocks
Qian Yu, Mohammad Ali Maddah-Ali, Salman Avestimehr, “Straggler Mitigation in Distributed Matrix Multiplication: Fundamental Limits and Optimal Coding”, Jan 2018, ISIT, TIT.
each worker 𝑗 computes
෩ 𝑩𝒋
𝑼
෩ 𝑪𝒋 ⋅
storage, communication
Allerton 2017
A better design for straggler mitigation (Entangled polynomial codes) Orderwise improvement for Secure, Private, Batch Matrix Multiplication
Qian Yu - Entangled Polynomial Codes (ISIT) July 2020
Qian Yu, Mohammad Ali Maddah-Ali, Salman Avestimehr, “Straggler Mitigation in Distributed Matrix Multiplication: Fundamental Limits and Optimal Coding”, Jan 2018, ISIT, TIT.
Relate works
𝑛𝑜(2𝑞 − 1) for 𝑛 = 𝑜
𝑞𝑛𝑜 + 𝑞 − 1
p × 𝑛 blocks p × 𝑜 blocks
Best known result
Entangled polynomial codes achieves Recovery threshold ≤ Theorem (Yu et al, Jan 2018)
Cubic ver. Sub-cubic ver.
Qian Yu - Entangled Polynomial Codes (ISIT) July 2020 All related works (Cubic interpretation, at least 𝒒𝒏𝒐 workers) Entangled Polynomial Codes: Order-wise coding gain for any large p,m,n
Qian Yu, Mohammad Ali Maddah-Ali, Salman Avestimehr, “Straggler Mitigation in Distributed Matrix Multiplication: Fundamental Limits and Optimal Coding”, Jan 2018, ISIT, TIT.
Qian Yu - Entangled Polynomial Codes (ISIT) July 2020
Entangled polynomial codes achieves Recovery threshold ≤ Theorem (Yu et al, Jan 2018)
Tensor decomposition since ~1960s Theorem: does not guarantee straggler resiliency What is missing?: Design codes for subcubic interpretation! All requiring at least 𝒒𝒏𝒐
𝒋
Aij
TBik
Relate works
Cubic interpretation
matrix by a 𝑞-by-𝑜 matrix.
large p,m,n
What if 𝑆 𝑞, 𝑛, 𝑜 not yet known? Sub-cubic upper bound exists for any large p,m,n
Qian Yu, Mohammad Ali Maddah-Ali, Salman Avestimehr, “Straggler Mitigation in Distributed Matrix Multiplication: Fundamental Limits and Optimal Coding”, Jan 2018, ISIT, TIT.
Qian Yu - Entangled Polynomial Codes (ISIT) July 2020
Entangled polynomial codes achieves Recovery threshold ≤ Theorem (Yu et al, Jan 2018)
Design codes for subcubic interpretation!
Cubic ver. Sub-cubic ver.
different coding structures
Entangled Polynomial Codes
Coded Computing Matrix Multiplication Algorithms Fault-Tolerant Computing Secure Matrix Multiplication Private Matrix Multiplication Batch Matrix Multiplication
Unified framework with
All related works (Cubic interpretation, at least 𝒒𝒏𝒐 workers) Entangled Polynomial Codes: Order-wise coding gain for any large p,m,n
Theorem (Entangled Polynomial Codes)
Qian Yu - Entangled Polynomial Codes (ISIT) July 2020
Qian Yu - Entangled Polynomial Codes (ISIT) July 2020
One/Two-sided secure:
One/Two of inputs information theoretically private against 𝑈 colluding workers
Secure Distributed Matrix Multiplication Private Distributed Matrix Multiplication Private:
Query D information theoretically private against any worker
Batch Distributed Matrix Multiplication Element-wise multiply two lists of matrices (Length: L) …and all possible mixtures
Qian Yu - Entangled Polynomial Codes (ISIT) July 2020
all possible mixtures Secure Private Batch
Relate works
…
Entangled polynomial codes achieves Recovery threshold ≤ Θ(𝑆(𝑞, 𝑛, 𝑜)) for all setting Theorem Straggler resiliency comes for free Remark 1 (Polynomial Coded Computing) Optimal within a factor of 2 Remark 2 (Converse)
Requiring 𝐩(𝒒𝒏𝒐) workers for all settings All built upon cubic interpretation require at least 𝒒𝒏𝒐 workers
Qian Yu - Entangled Polynomial Codes (ISIT) July 2020
Entangled polynomial codes achieves recovery threshold ≤ 2𝑆 𝑞, 𝑛, 𝑜 − 1
Theorem (Secure Distributed Matrix Multiplication) Example 1: Secure Distributed Matrix Multiplication
State of the arts
Require at least 𝒒𝒏𝒐 +𝑼 workers for one-sided security +𝟑𝑼 workers for one-sided security
One/Two-sided secure:
One/Two of inputs information theoretically private against 𝑈 colluding workers
Secure Distributed Matrix Multiplication
+𝑈 for one-sided security +2𝑈 for two-sided security
Qian Yu - Entangled Polynomial Codes (ISIT) July 2020
Entangled polynomial codes achieves recovery threshold ≤ 2𝑆 𝑞, 𝑛, 𝑜 − 1
Theorem (Secure Distributed Matrix Multiplication) Example 1: Secure Distributed Matrix Multiplication
One/Two-sided secure:
One/Two of inputs information theoretically private against 𝑈 colluding workers
Secure Distributed Matrix Multiplication
+𝑈 for one-sided security +2𝑈 for two-sided security
Step 1: tensor decomposition Two vectors of length 𝑆(𝑞, 𝑛, 𝑜) suffice to compute their elementwise product
Qian Yu - Entangled Polynomial Codes (ISIT) July 2020
Entangled polynomial codes achieves recovery threshold ≤ 2𝑆 𝑞, 𝑛, 𝑜 − 1
Theorem (Secure Distributed Matrix Multiplication) Example 1: Secure Distributed Matrix Multiplication
One/Two-sided secure:
One/Two of inputs information theoretically private against 𝑈 colluding workers
Secure Distributed Matrix Multiplication
+𝑈 for one-sided security +2𝑈 for two-sided security
Step 2: Optimal coding for elementwise product
No security requirement One-sided secure Pad by 𝑈 random keys Pad by 𝑈 random keys Pad by 𝑈 random keys Two-sided secure
Satisfies security requirement Does not interferer decodability Each padded key increases degree by 1 Recovery threshold +T Recovery threshold +2T QED
Qian Yu - Entangled Polynomial Codes (ISIT) July 2020
State of the art
Require at least 𝐌𝒒𝒏𝒐 workers
Example 2: Batch Distributed Matrix Multiplication
QED 𝒑(𝑴𝒒𝒏𝒐)