uncovering spoken phrases in encrypted voip conversations by, ritesh chandra reddy gunna. prasad...
TRANSCRIPT
Uncovering spoken phrases in encrypted VoIP conversations
BY,
RITESH CHANDRA REDDY GUNNA.
PRASAD VUNNAM.
Authors
Charles V. Wright
Lucas Ballard
Scott E. Coull
Fabian Monrose
Gerald M. Masson
Introduction
Encrypted data is sent through VoIP.
We need to check the efficiency.
Hack the voice data over IP.
Capturing Voice
Voice is captured using HMM.
HMM- Hidden Markov Model.
Uses the phonetic pronunciation of the words from the database.
TIMIT- It is the database that contains the phonetic words.
Codecs and software used
Speex codec: This codec is used to encode the recordings from TIMIT which is used to find the relationship between the bit rates. This all happens in wideband. When coming to the narrow band, it is used to test the precision between narrow band and wide band.
HMER: It is a software package that is used to build Hidden Morkov Model (HMM) to recognize the English phrases and pronunciation.
CELP Encoder (Code exited linear prediction)
Distribution of bit rates usedto encode four phonemes with
Speex
Training and Detection Process
Extendibility
We can also use languages other than English which was not done in this paper.
For this we need to develop phonetic pronunciation libraries called TIMIT for different languages.
Conclusion
The intention of the authors of this paper is to find out all the possibilities of hacking the voice over IP and then find out for the remedies. That is the methods to protect the data over IP and to improve them to give more efficient results.
THANK YOU