Behind the curtain: Oblivious Transfer

Lyubomir Filipov                                                           @FilipovG

Who am I

Lyubomir Filipov

Team Lead

Enthusiast
 

Oblivious transfer

cryptographic primitive

1-out-of-2 OT: Alice chooses as input two bits b0 and b1. Bob chooses a selection bit c and gets as output the bit bc.

Bananas in Pyjamas

Oblivious transfer

Alice should not learn c
Bob should not learn b1-c

Alice

Bob

Oblivious transfer

Only one item is returned to Bob.
Alice won't know what Bob has in his mind!

Oblivious transfer

Biometric data

personal data resulting from specific technical processing relating to the physical, physiological or behavioural characteristics of a natural person, which allow or confirm the unique identification of that natural person.

Biometric data

Fingerprint scanning

Iris recognition

Biometric data

Not 100% perfect


Every scan will return different results

Data representation

Hamming distance

Privacy-preserving biometric identification

• Anonymous Biometric access Control
   
• Biometric Anonymous Credentials
   
• Secure Biometric Database Intersection

Biometric identification

SHADE protocol

SHADE protocol

SHADE protocol

SHADE protocol

SHADE protocol

SHADE protocol

SHADE protocol

SHADE protocol

SHADE protocol

Where it could be applied

• Dating app where you only want to receive messages from one user.
   
• IoT devices that send sensitive data.

But, wait

To be aware of

• All this comes as extra traffic
   
• It could not be extended easily

Questions?