2019-02-13 Wednesday - Homomorphic Encryption

An interesting discussion arose in the last week, which introduced me to the concepts of using Homomorphic Encryption in machine learning solutions.



https://en.wikipedia.org/wiki/Homomorphic_encryption


IBM's Blindfolded Calculator 

• https://www.forbes.com/forbes/2009/0713/breakthroughs-privacy-super-secret-encryption.html#295deb7a7124

A very casual introduction to Fully Homomorphic Encryption

• https://blog.cryptographyengineering.com/2012/01/02/very-casual-introduction-to-fully/

Encrypt your Machine Learning
How Practical is Homomorphic Encryption for Machine Learning?

• https://medium.com/corti-ai/encrypt-your-machine-learning-12b113c879d6

A FULLY HOMOMORPHIC ENCRYPTION SCHEME 

• A DISSERTATION SUBMITTED TO THE DEPARTMENT OF COMPUTER SCIENCE AND THE COMMITTEE ON GRADUATE STUDIES OF STANFORD UNIVERSITY IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY

• Craig Gentry, September 2009

• http://cs.au.dk/~stm/local-cache/gentry-thesis.pdf

A brief survey of Fully Homomorphic Encryption, computing on encrypted data

• https://blog.quarkslab.com/a-brief-survey-of-fully-homomorphic-encryption-computing-on-encrypted-data.html

Homomorphic EncryptionShai Halevi (IBM Research)April 2017

• https://shaih.github.io/pubs/he-chapter.pdf

"Fully  homomorphic  encryption  (FHE)  has  been  called  the  “Swiss  Army  knife  of  cryptog-raphy”,  since  it  provides  a  single  tool  that  can  be  uniformly  applied  to  many  cryptographicapplications.  In this tutorial we study FHE and describe its different properties, relations withother concepts in cryptography, and constructions.  We briefly discuss the three generations ofFHE constructions since Gentry’s breakthrough result in 2009,  and cover in detail the third-generation scheme of Gentry, Sahai, and Waters (GSW)"

Fully Homomorphic Encryption: Cryptography’s Holy Grail 

• https://www.cs.virginia.edu/dwu4/papers/XRDSFHE.pdf   
  

Cryptology ePrint Archive: Report 2015/1192
A Guide to Fully Homomorphic Encryption

• https://eprint.iacr.org/2015/1192

2012-10-02 Tuesday - SHA-3 winner (Keccak)

http://csrc.nist.gov/groups/ST/hash/sha-3/winner_sha-3.html

NIST announced Keccak as the winner of the SHA-3 Cryptographic Hash Algorithm Competition and the new SHA-3 hash algorithm in a press release issued on October 2, 2012. Keccak was designed by a team of cryptographers from Belgium and Italy, they are:

• Guido Bertoni (Italy) of STMicroelectronics,
• Joan Daemen (Belgium) of STMicroelectronics,
• Michaël Peeters (Belgium) of NXP Semiconductors, and
• Gilles Van Assche (Belgium) of STMicroelectronics.

http://keccak.noekeon.org/
From keccak web site:

Keccak makes use of the sponge construction and is hence a sponge function family.
The design philosophy of Keccak is the hermetic sponge strategy. It uses the sponge construction for having provable security against all generic attacks. It calls a permutation that should not have structural properties with the exception of a compact description. By structural properties we mean properties that a typical random permutation does not have.

Keccak can be considered as a successor of RadioGatún. However, it has a very different design philosophy. The transformation applied to the state of RadioGatún in between the insertion of input blocks or extraction of output blocks is a simple round function. This round function has algebraic degree two and thus does not attempt to be free of structural properties. Therefore, unlike Keccak, RadioGatún requires blank rounds. Moreover, RadioGatún is not a sponge function as its iteration mode does not follow the sponge construction.
The permutation Keccak-f has the following properties:

• It consists of the iteration of a simple round function, similar to a block cipher without a key schedule.
• The nominal version of Keccak-f operates on a 1600-bit state. There are 6 other state widths, though: 25, 50, …, 800.
• The choice of operations is limited to bitwise XOR, AND and NOT and rotations. There is no need for table-lookups, arithmetic operations, or data-dependent rotations.

About the performance of Keccak:

• In software, Keccak[] takes about 13 cycles per byte on the reference platform defined by NIST.
• In hardware, it is fast and compact, with area/speed trade-offs.
• It is suitable for DPA-resistant implementations both in hardware and software.

Keccak can be used for:

• keyed or randomized modes simply by prepending a key or salt to the input message;
• generating infinite outputs, making it suitable as a stream cipher or mask generating function.

In these cases, the usage of the sponge construction allows for modes that are provably secure against generic attacks.

2010-06-06 Sunday - Cryptography Resources

Some recent design work in the area of securing data-at-rest, and data-in-motion - particularly in relation to the requirements for Payment Card Industry (PCI) [i.e. credit/debit card information, bank account information, etc.] and Personal Information / Highly Confidential Data (i.e. social security number, driver license, passport, etc.) has raised my awareness of some new regulatory and legal compliance challenges (new MA law: Chapter 82 of the Acts of 2007) in designing security into an effective architecture.

State Security Breach Notification Laws

A few resources that may be of interest to others working on similar efforts:

PCI Quick Reference Guide

http://www-03.ibm.com/security/cryptocards/


http://domino.research.ibm.com/comm/research_projects.nsf/pages/security.index.html


http://www-03.ibm.com/security/products/cryptotools.shtml



































































2010-06-12 Update:
I came across this link today (via Slashdot):
Computing with Secrets, but Keeping them Safe

In 2009 Craig Gentry of IBM published a cryptographic proof that was that rare thing: a true breakthrough. He showed that it was possible to add and multiply encrypted data to produce a result that--when decrypted--reveals the result of performing the same operations on the original, unencrypted data. It's like being able to answer a question without knowing what the question is.

Called "fully homomorphic encryption," it has been dubbed the holy grail of cryptography.