Inverse Free HCTR: A Length Preserving Tweakable Enciphering Mode.

Date of Submission

December 2018

Date of Award

Winter 12-12-2019

Institute Name (Publisher)

Indian Statistical Institute

Document Type

Master's Dissertation

Degree Name

Master of Technology

Subject Name

Computer Science


Cryptology and Security Research Unit (CSRU-Kolkata)


Chakraborty, Debrup (CSRU-Kolkata; ISI)

Abstract (Summary of the Work)

Inverse Free HCTR (IFHCTR) is a length-preserving encryption scheme, which provides a tweakable strong pseudorandom permutation. IFHCTR is modification of HCTR scheme in which inverse of block cipher is not required. IFHCTR supports arbitrary variable input length with the minore restriction that data should be at least 2n bits long, where n is the block length of block cipher. IFHCTR also supports variable length tweaks. We prove that IFHCTR is a strong tweakable pseudorandom permutation (sprp), when the underlying blockcipher is a pseudorandom function (prf). IFHCTR can be used in disk sector encryption, and other applications where length-preserving encryptions are required, especially when size of the message is not multiple of n bits.


ProQuest Collection ID:

Control Number


Creative Commons License

Creative Commons Attribution 4.0 International License
This work is licensed under a Creative Commons Attribution 4.0 International License.


This document is currently not available here.