Die Präsentation von Matthias Gusenbauer erklärt, was sichere Berechnung ist und warum sie wichtig ist, insbesondere durch Techniken wie Secure Multiparty Computation (MPC) und Fully Homomorphic Encryption (FHE). Diese Methoden ermöglichen es, auf verschlüsselten Daten zu rechnen, sodass Privatsphäre und Sicherheit gewahrt bleiben. MPC hat Anwendungen in Bereichen wie maschinelles Lernen und Datenschutz, während es gleichzeitig vertrauenswürdige Dritte ersetzen kann.

1. Klassifikation: Öffentlich
Welcome
to the SBA LiveAcademy
#bleibdaheim #remotelearning
Today: What the Heck is Secure Computing?
by Matthias Gusenbauer
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2. Klassifikation: Öffentlich
What the Heck is Secure Computing
and why should I care?
SBA Research gGmbH, 2020

3. Klassifikation: Öffentlich 3
Whatis Secure Computing?
• Compute on encrypted data
o Secure Multiparty Computation (MPC)
– Jointly compute on private data
– "Data sharing without sharing data"
o Fully Homomorphic Encryption (FHE)
– Compute on ciphertext
– Outsource computation without losing privacy
SBA Research gGmbH, 2020

4. Klassifikation: Öffentlich 4
MPC vs FHE
+ - Basis
MPC
• Faster
• More tool choice
• More
communication
• Secret sharing
• Oblivioustransfer
FHE
• Less
communication
• Slower
• Less tool choice
• Mathematical
properties of
ciphertext
SBA Research gGmbH, 2020

5. Klassifikation: Öffentlich 5
MPC Example
• Average salary of Academy participants
• Only learn output (nothing else)
• Secret sharing
o Additive Secret Sharing
SBA Research gGmbH, 2020

6. Klassifikation: Öffentlich 6
MPC Example
SBA Research gGmbH, 2020
Z1: 2500 EUR
Z2: 2350 EURZ3: 2000 EUR

7. Klassifikation: Öffentlich 7
MPC Example
SBA Research gGmbH, 2020
Z1: 2500 EUR
S1,1=1000
S1,2=250
S1,3=1250
Z2: 2350 EUR
S2,1=150
S2,2=700
S2,3=1500
Z3: 2000 EUR
S3,1=300
S3,2=800
S3,3=900

8. Klassifikation: Öffentlich 8
MPC Example
SBA Research gGmbH, 2020
Z1: 2500 EUR
S1,1=1000
S1,2=250
S1,3=1250
Z2: 2350 EUR
S2,1=150
S2,2=700
S2,3=1500
Z3: 2000 EUR
S3,1=300
S3,2=800
S3,3=900
S3,2 | S2,3

9. Klassifikation: Öffentlich 9
MPC Example
SBA Research gGmbH, 2020
Z1: 2500 EUR
S1,1=1000
S1,2=250
S1,3=1250
Z2: 2350 EUR
S2,1=150
S2,2=700
S2,3=1500
Z3: 2000 EUR
S3,1=300
S3,2=800
S3,3=900
Add S1,1+S2,1+S3,1
T1=1000+150+300=1450
Add S2,2+S1,2+S3,2
T2=700+250+800=1750
Add S3,3+S1,3+S2,3
T3=900+1250+1500=3650

10. Klassifikation: Öffentlich 10
MPC Example
SBA Research gGmbH, 2020
Z1: 2500 EUR
S1,1=1000
S1,2=250
S1,3=1250
Z2: 2350 EUR
S2,1=150
S2,2=700
S2,3=1500
Z3: 2000 EUR
S3,1=300
S3,2=800
S3,3=900
Add S1,1+S2,1+S3,1
T1=1000+150+300=1450
Add S2,2+S1,2+S3,2
T2=700+250+800=1750
Add S3,3+S1,3+S2,3
T3=900+1250+1500=3650
T3 | T2

11. Klassifikation: Öffentlich 11
MPC Example
SBA Research gGmbH, 2020
Z1: 2500 EUR
S1,1=1000
S1,2=250
S1,3=1250
Z2: 2350 EUR
S2,1=150
S2,2=700
S2,3=1500
Z3: 2000 EUR
S3,1=300
S3,2=800
S3,3=900
Add S1,1+S2,1+S3,1
T1=1000+150+300=1450
Add S2,2+S1,2+S3,2
T2=700+250+800=1750
Add S3,3+S1,3+S2,3
T3=900+1250+1500=3650
T1+T2+T3=SumFinal
Average=SumFinal/3 = 2283,33

12. Klassifikation: Öffentlich 12
MPC Use Cases
SBA Research gGmbH, 2020
Awesome Company
C1
C3 C2
SecurityPrivacy

13. Klassifikation: Öffentlich 13
MPC Use Cases
• Privacy
o Machine learning
o Credit score computation
o Combining health data
• Security
o System resiliency
o Remove single point of failure (e.g. key splitting)
o Protection of assets
SBA Research gGmbH, 2020

14. Klassifikation: Öffentlich 14
ImportantConsiderations
• 2PC or MPC?
• Honest or dishonest majority?
• Semi-honest or malicious security?
• Cryptography knowledge in house?
o Some pitfalls (inadvertent leakage, performance)
• Open to work with research code?
o Proprietary platforms (tech support)
o Open source tools (more choices)
SBA Research gGmbH, 2020

15. Klassifikation: Öffentlich 15
Existing Tools
• Proprietary
o Unbound
o Cybernetica (Sharemind)
• Open source
o JIFF
o Scale-Mamba
o …
SBA Research gGmbH, 2020

16. Klassifikation: Öffentlich 16
My 3 Key Take-Aways
1. Secure Computation is possible (MPC)
2. MPC replaces trusted third parties
3. MPC can enable new business cases and
increase my security
SBA Research gGmbH, 2020

17. Klassifikation: Öffentlich 17
My Study
• MPC adoption and lack thereof
• 30-45 minute interview (recorded – 20 EUR
Amazon voucher)
• Strict protection of participants' privacy
• https://de.surveymonkey.com/r/PCB29X9 (or
send me an email)
SBA Research gGmbH, 2020

18. Klassifikation: Öffentlich 18
Matthias Gusenbauer
SBA Research gGmbH
Floragasse 7, 1040 Wien
MGusenbauer@sba-research.org
SBA Research gGmbH, 2020

19. Klassifikation: Öffentlich 19
ProfessionalServices
Penetration Testing
Architecture Reviews
Security Audit
Security Trainings
Incident Response Readiness
ISMS & ISO 27001 Consulting
Bridging Science and Industry
Applied Research
Industrial Security| IIoT Security|
Mathematics for SecurityResearch |
Machine Learning| Blockchain | Network
Security| Sustainable Software Systems |
Usable Security
SBAResearch
Knowledge Transfer
SBA Live Academy | sec4dev | Trainings |
Events | Teaching | sbaPRIME
Contact us: anfragen@sba-research.org

20. Klassifikation: Öffentlich 20
References
• Character images "Shadow Tactics – Blades of the
Shogun
• MPC overview paper "SoK: General Purpose
Compilers for Secure Multi-Party Computation"
by Hastings et al.
• Unbound - https://www.unboundtech.com/
• Sharemind - https://sharemind.cyber.ee/
SBA Research gGmbH, 2020

21. Klassifikation: Öffentlich 21
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22. Klassifikation: Öffentlich 22
Abschnitt
Untertitel für Abschnitt
SBA Research gGmbH, 2020

23. Klassifikation: Öffentlich 23
MPC Example
SBA Research gGmbH, 2020
Z1: 2500 EUR
S1,1=1000
S1,2=250
S1,3=1250
Z2: 2350 EUR
S2,1=150
S2,2=700
S2,3=1500
Z3: 2000 EUR
S3,1=300
S3,2=800
S3,3=900
Add S1,1+S2,1+S3,1
T1=1000+150+300=1450
Add S2,2+S1,2+S3,2
T2=700+250+800=1750
Add S3,3+S1,3+S2,3
T3=900+1250+1500=3650
T1+T2+T3=SumFinal
Average=SumFinal/3
S3,2 | S2,3

24. Klassifikation: Öffentlich 24
MPC Example
SBA Research gGmbH, 2020
Z1: 2500 EUR
S1,1=1000
S1,2=250
S1,3=1250
Z2: 2350 EUR
S2,1=150
S2,2=700
S2,3=1500
Z3: 2000 EUR
S3,1=300
S3,2=800
S3,3=900
Add S1,1+S2,1+S3,1
T1=1000+150+300=1450
Add S2,2+S1,2+S3,2
T2=700+250+800=1750
Add S3,3+S1,3+S2,3
T3=900+1250+1500=3650
T1+T2+T3=SumFinal
Average=SumFinal/3
T3 | T2