Biblio

Nowadays a huge amount of sensitive information is sending via packet data networks and its security doesn't provided properly. Very often information leakage causes huge damage to organizations. One of the mechanisms to cause information leakage when it transmits through a communication channel is to construct a covert channel. Everywhere used packet networks provide huge opportunities for covert channels creating, which often leads to leakage of critical data. Moreover, covert channels based on packet length modifying can function in a system even if traffic encryption is applied and there are some data transfer schemes that are difficult to detect. The purpose of the paper is to construct and examine a normalization protection tool against covert channels. We analyze full and partial normalization, propose estimation of the residual covert channel capacity in a case of counteracting and determine the best parameters of counteraction tool.

Currently, packet data networks are widespread. Their architectural features allow constructing covert channels that are able to transmit covert data under the conditions of using standard protection measures. However, encryption or packets length normalization, leave the possibility for an intruder to transfer covert data via timing covert channels (TCCs). In turn, inter-packet delay (IPD) normalization leads to reducing communication channel capacity. Detection is an alternative countermeasure. At the present time, detection methods based on machine learning are widely studied. The complexity of TCCs detection based on machine learning depends on the availability of traffic samples, and on the possibility of an intruder to change covert channels parameters. In the current work, we explore the cases of TCCs detection via

Nowadays one-time passwords are used in a lot of areas of information technologies including e-commerce. A few vulnerabilities in authentication protocols based on one-time passwords are widely known. In current work, we analyze authentication protocols based on one-time passwords and their vulnerabilities. Both simple and complicated protocols which are implementing cryptographic algorithms are reviewed. For example, an analysis of relatively old Lamport's hash-chain protocol is provided. At the same time, we examine HOTP and TOTP protocols which are actively used nowadays. The main result of the work are conclusions about the security of reviewed protocols based on one-time passwords.