Generation of random keys for cryptographic systems

Mariusz Borowski,Robert Wicik,Marcin Grzonkowski,Marek Leśniewicz

doi:10.2478/v10065-012-0033-z

Abstract

Military and government institutions need security services for storing and exchanging classified information among them. Security of such information is important for independence of the State. At present, cryptography provides a lot of methods for information security. A one-time pad cipher may be used to ensure perfect (unconditional) security. There are many ciphers and other cryptographic transformations, which are not perfect, but ensure conditional security adequate to needs. All cryptosystems require keys and other crypto materials. These keys should satisfy numerous conditions. The basic is randomness. One of the best sources of random bit sequences used in the production of keys for special cryptosystems is a hardware generator. Now we have an electronic device, where it is possible to generate binary random sequences with the potential output rate of 100 Mbit/s. It gives us the capability of building an efficient key generation equipment for the cryptosystems to rely on the one-time pad cipher, where we need very long keys and for those based on symmetric or asymmetric transformations where many relatively short keys are needed.

Highlights

Classified information, as defined by the Polish law: “Protection of classified information act”, is divided into four clauses: top secret, secret, confidential and restricted
It is important to recall that the messages encrypted in 1950’s with the ’state of the art’ not perfect cipher machines kept archived by the adversary are generally broken within a few seconds, minutes or some hours at most
The one-time pad (OTP), called the Vernam-cipher or the perfect cipher, is a crypto algorithm where a plaintext is combined with a random key

Summary

Introduction

Classified information, as defined by the Polish law: “Protection of classified information act”, is divided into four clauses: top secret, secret, confidential and restricted. The perfect cipher requires random keys as long as the plaintext, a data management system and a robust, trusted key distribution system. One of the basic problems in the key generation systems is an efficient source of random bit sequences. In the Military Communication Institute (MCI), since the nineties we have been developing hardware random number generators and key generation systems for cryp-. U tographic systems based on perfect and no perfect ciphers utilizing one-time, private and public keys. We have possibility of hardware generation of binary random sequences with the potential bit rate 100 Mbit/s. It will eliminate the restrictions connected with availability of very long one-time keys for perfect ciphering and many short keys for non perfect ciphering

One-Time Pad

Realization of the SGCL-100M generator

Planning secure connections

Generation of one-time keys

Generation of keys for non perfect cryptosystems

Conclusions