1,418 research outputs found

    Evaluation of preprocessors for neural network speaker verification

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    When keystroke meets password: Attacks and defenses

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    Integration of speech biometrics in a phone payment system: text-independent speaker verification

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    Integration of a speaker recognition system in a payment system by phone.Nowadays, the integration of biometrics in security systems is a prominent research and application field. Also, it is clear that speech is the most common form of communication, which makes a swell candidate. While using speech as a biometric, one could say there are two types of systems that should be analyzed: those systems which do know what the speaker is going to say upon verification and those that do not. This degree thesis offers an overview of both systems, focusing on those that do not know what the speaker is going to say beforehand, also known as textindependent systems. To be able to determine which would be the best approach to integrate speech biometrics into a security system, both types of systems are compared; and two methodologies are also analyzed for the text-independent system. To conclude, one of those methodologies is implemented in a software library which allows the creation a text-independent speaker verification system.En l’actualitat, la integració de biometries en els sistemes de seguretat és una branca d’investigació i aplicacions prominent. A més a més, la veu és un dels mitjans més comuns de comunicació, cosa que fa que sigui una bona candidata per a aquests sistemes. Si prenem la parla com a biometria, es pot dir que hi ha dos tipus de sistemes bastant diferenciats a analitzar: aquells sistemes els quals saben el que dirà la persona que s’intenta verificar i aquells que no saben el que dirà. Aquest treball ofereix una visió àmplia dels dos tipus de sistemes, centrant-se en els sistemes on no es sap el que es dirà, també coneguts com sistemes de text independent. Per decidir quin seria la millor manera d’integrar la parla com a biometria en un sistema de seguretat, es comparen ambdós sistemes i, en el cas del sistema de text independent, es comparen també dues metodologies diferents. Per acabar, s’implementa una d’aquestes metodologies a unes llibreries de software per dur a terme un sistema de verificació de locutor amb text independent.En la actualidad, la integración de biometrías en los sistemas de seguridad es una rama de investigación y de aplicaciones prominente. Además, está claro que la voz es el medio más común de comunicación y es por eso que es una buena candidata. Usando el habla como biometría, se podría decir que hay dos tipos de sistemas diferentes a analizar: aquellos sistemas que saben de antemano aquello que va a decir el locutor que intenta verificarse y aquellos que no lo saben. Este trabajo ofrece una visión amplia de los dos tipos de sistemas, centrándose en los sistemas donde aquello que se va a decir no se sabe, también conocidos como sistemas de texto independiente. Para decir cuál sería la mejor manera de integrar el habla como biometría en un sistema de seguridad se comparan ambos sistemas y, en el caso del sistema de texto independiente, se comparan también dos metodologías diferentes. Para finalizar, se implementa una de estas últimas en unas librerías de software para poder llevar a cabo un sistema de verificación de locutor de texto independiente

    User-Customized Password Speaker Verification Using Multiple Reference and Background Models

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    This paper discusses and optimizes an HMM/GMM based User-Customized Password Speaker Verification (UCP-SV) system. Unlike text-dependent speaker verification, in UCP-SV systems, customers can choose their own passwords with no lexical constraints. The password has to be pronounced a few times during the enrollment step to create a customer dependent model. Although potentially more ``user-friendly'', such systems are less understood and actually exhibit several practical issues, including automatic HMM inference, speaker adaptation, and efficient likelihood normalization. In our case, HMM inference (HMM topology) is performed using hybrid HMM/MLP systems, while the parameters of the inferred model, as well as their adaptation, will use GMMs. However, the evaluation of a UCP-SV baseline system shows that the background model used for likelihood normalization is the main difficulty. Therefore, to circumvent this problem, the main contribution of the paper is to investigate the use of multiple reference models for customer acoustic modeling and multiple background models for likelihood normalization. In this framework, several scoring techniques are investigated, such as Dynamic Model Selection (DMS) and fusion techniques. Results on two different experimental protocols show that an appropriate selection criteria for customer and background models can improve significantly the UCP-SV performance, making the UCP-SV system quite competitive with a text-dependent SV system. Finally, as customers' passwords are short, a comparative experiment using the conventional GMM-UBM text-independent approach is also conducted

    Semi-continuous hidden Markov models for automatic speaker verification

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    Mobile Biometric Challenge Recording Interface

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    Autentimine arvutivõrkudes on protsess, mis üritab kontrollida digitaalset identiteeti, kasutades paroole. Parooli olemasolu aitab tagada kasutaja autentsuse. Kasutajaid saab biomeetiriliselt kindlaks teha ka nende sõrmejälje, hääle või näo järgi kasutades kindlat riistvara ja parooli toimingu kinnitamiseks. Samas, juhul kui paljud kasutajad on seotud sedatüüpi autentimisega, võib selline lahendus muutuda liiga aeglaseks ja suhteliselt kulukaks. Seetõttu vajab edukas biomeetriline autentimise süsteem põhjalikku läbimõeldust paljude tegurite osas (PBworks, 2007). Minu magistritöö eesmärk on uurida erinevaid biomeetrilise autentimise meetodeid, luues kirjeldused mobiilseks kasutamiseks ning töötada välja ja realiseerida vastav prototüüp. Kui biomeetrilise testi andmed on kogutud, näiteks video või hale kaudu, siis saadud andmed läbivad töötluse, peale mida kasutatakse ainult unikaalset osa andmetest. See osa andmetest salvestatakse andmebaasi. Kuid, enne andmete kasutamist, tuleb telefonis rakendada mitmeid meetmeid. Biomeetria puhul kasutatakse kahte peamist stsenaariumit: kontrollimine ja isikuandmete tuvastamine. Kontrollimise puhul võrreldakse ainult ühte andmebaasi, mis on kirjeldatav kui üks-ühele võrdulus. Isikuandmete tuvastamisel kasutatakse üks-mitmele andmebaaside võrdlust. Mõlemal juhul peavad salvestatud andembaasid toetama vastavaid stsenaariume. Magistritöös valmis vastav kasutajaliides nõutud omadustega.Mobile Biometric Challenge Recording Interface In computer network, authentication is the process of attempting to verify the digital identity using login passwords. Knowledge of the password is presumed to guarantee that the user is authentic. Likewise, Users may biometrically authenticate via their fingerprint, voice, face, or using provided hardware and password to confirm the operation. However, when many of users are involved this type of authentication is not suitable because this solution may become too slow and relatively expensive. In brief, successful distribution of a biometric authentication system needs careful deliberation of many factors (PBworks, 2007). My thesis core will be to study different biometric authentication techniques, derive requirements from these for a mobile interface, and implement and refine an interface prototype. When a biometric sample or trait is acquired, such as a video or a voice sample, the captured data goes through some amount of processing to prepare it for the extraction of a relatively small set of numbers, which represent the unique aspects of the data. This extracted set of data in record called a recording template. However, to prepare this recording optimally for biometric algorithms several measures already have to be taken on the phone. There are two basic usage scenarios for biometrics, known as verification and identification. Verification is the scenario where a newly created template is compared with only one other template in a database, which is described as an one-to-one comparison. The second biometric usage scenario is called identification, which is used when it is necessary to compare a newly created template too many enrolled templates, which is described as an one-to-many comparison

    Towards Implementing An Efficient Biometric Authentication Framework For Nigeria Customer Banking Systems

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    With the rapidly increasing number of break-in reports on traditional Personal Identification Number (PIN) and password security systems, there is a high demand for greater security for access to sensitive or personal information in the Nigerian Banking System. This paper reviews the current practices in Nigeria’s customer banking services; reveals the results of a survey and suggests a more efficient biometric framework for a more secured Nigeria Customer Banking System. Customer banking, which includes a wide spectrum of banking services, must be carried out with proper authentication to ensure not only the security of transactions, customers’ information and funds, but also the protection of the Banks’ global image and brand. It is clear that Information Security and Information Management tend to interrelate in innovative systems thereby triggering the need for sustainability. The uses of traditional forms of authentication such as signatures, Identity cards and PIN have not adequately met this security need. In recent times, biometric technologies have been typically used to analyze human characteristics for security purposes as biometric-based authentication serves as a solidified form of authentication for real-time security processes
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