Security strategies in genomic files

There are new mechanisms to sequence and process the genomic code, discovering thus diagnostic tools and treatments. The file for a sequenced genome can reach hundreds of gigabytes. Thus, for further studies, we need new means to compress the information and a standardized representation to simplify the development of new tools. The ISO standardization group MPEG has used its expertise in compressing multimedia content to compress genomic information and develop its ´MPEG-G standard’. Given the sensitivity of the data, security is a major identified requirement. This thesis proposes novel technologies that assure the security of both the sequenced data and its metadata. We define a container-based file format to group data, metadata, and security information at the syntactical level. It includes new features like grouping multiple results in a same file to simplify the transport of whole studies. We use the granularity of the encoder’s output to enhance security. The information is represented in units, each dedicated to a specific region of the genome, which allows to provide encryption and signature features on a region base. We analyze the trade-off between security and an even more fine-grained approach and prove that apparently secure settings can be insecure: if the file creator may encrypt only specific elements of a unit, cross-checking unencrypted information permits to infer encrypted content. Most of the proposals for MPEG-G coming from other research groups and companies focused on data compression and representation. However, the need was recognized to find a solution for metadata encoding. Our proposal was included in the standard: an XML-based solution, separated in a core specification and extensions. It permits to adapt the metadata schema to the different genomic repositories' frameworks, without importing requirements from one framework to another. To simplify the handling of the resulting metadata, we define profiles, i.e. lists of extensions that must be present in a given framework. We use XML signature and XML encryption for metadata security. The MPEG requirements also concern access rules. Our privacy solutions limit the range of persons with access and we propose access rules represented with XACML to convey under which circumstances a user is granted access to a specific action among the ones specified in MPEG-G's API, e.g. filtering data by attributes. We also specify algorithms to combine multiple rules by defining default behaviors and exceptions. The standard’s security mechanisms protect the information only during transport and access. Once the data is obtained, the user could publish it. In order to identify leakers, we propose an algorithm that generates unique, virtually undetectable variations. Our solution is novel as the marking can be undone (and the utility of the data preserved) if the corresponding secret key is revealed. We also show how to combine multiple secret keys to avoid collusion. The API retained for MPEG-G considers search criteria not present in the indexing tables, which highlights shortcomings. Based on the proposed MPEG-G API we have developed a solution. It is based on a collaboration framework where the different users' needs and the patient's privacy settings result in a purpose-built file format that optimizes query times and provides privacy and authenticity on the patient-defined genomic regions. The encrypted output units are created and indexed to optimize query times and avoid rarely used indexing fields. Our approach resolves the shortcomings of MPEG-G's indexing strategy. We have submitted our technologies to the MPEG standardization committee. Many have been included in the final standard, via merging with other proposals (e.g. file format), discussion (e.g. security mechanisms), or direct acceptance (e.g. privacy rules).Hi han nous mètodes per la seqüenciació i el processament del codi genòmic, permetent descobrir eines de diagnòstic i tractaments en l’àmbit mèdic. El resultat de la seqüenciació d’un genoma es representa en un fitxer, que pot ocupar centenars de gigabytes. Degut a això, hi ha una necessitat d’una representació estandarditzada on la informació és comprimida. Dins de la ISO, el grup MPEG ha fet servir la seva experiència en compressió de dades multimèdia per comprimir dades genòmiques i desenvolupar l'estàndard MPEG-G, sent la seguretat un dels requeriments principals. L'objectiu de la tesi és garantir aquesta seguretat (encriptant, firmant i definint regles d¿ accés) tan per les dades seqüenciades com per les seves metadades. El primer pas és definir com transportar les dades, metadades i paràmetres de seguretat. Especifiquem un format de fitxer basat en contenidors per tal d'agrupar aquets elements a nivell sintàctic. La nostra solució proposa noves funcionalitats com agrupar múltiples resultats en un mateix fitxer. Pel que fa la seguretat de dades, la nostra proposta utilitza les propietats de la sortida del codificador. Aquesta sortida és estructurada en unitats, cadascuna dedicada a una regió concreta del genoma, permetent una encriptació i firma de dades específica a la unitat. Analitzem el compromís entre seguretat i un enfocament de gra més fi demostrant que configuracions aparentment vàlides poden no ser-ho: si es permet encriptar sols certes sub-unitats d'informació, creuant els continguts no encriptats, podem inferir el contingut encriptat. Quant a metadades, proposem una solució basada en XML separada en una especificació bàsica i en extensions. Podem adaptar l'esquema de metadades als diferents marcs de repositoris genòmics, sense imposar requeriments d’un marc a un altre. Per simplificar l'ús, plantegem la definició de perfils, és a dir, una llista de les extensions que han de ser present per un marc concret. Fem servir firmes XML i encriptació XML per implementar la seguretat de les metadades. Les nostres solucions per la privacitat limiten qui té accés a les dades, però no en limita l’ús. Proposem regles d’accés representades amb XACML per indicar en quines circumstàncies un usuari té dret d'executar una de les accions especificades a l'API de MPEG-G (per exemple, filtrar les dades per atributs). Presentem algoritmes per combinar regles, per tal de poder definir casos per defecte i excepcions. Els mecanismes de seguretat de MPEG-G protegeixen la informació durant el transport i l'accés. Una vegada l’usuari ha accedit a les dades, les podria publicar. Per tal d'identificar qui és l'origen del filtratge de dades, proposem un algoritme que genera modificacions úniques i virtualment no detectables. La nostra solució és pionera, ja que els canvis es poden desfer si el secret corresponent és publicat. Per tant, la utilitat de les dades és mantinguda. Demostrem que combinant varis secrets, podem evitar col·lusions. L'API seleccionada per MPEG-G, considera criteris de cerca que no són presents en les taules d’indexació. Basant-nos en aquesta API, hem desenvolupat una solució. És basada en un marc de col·laboració, on la combinació de les necessitats dels diferents usuaris i els requeriments de privacitat del pacient, es combinen en una representació ad-hoc que optimitza temps d’accessos tot i garantint la privacitat i autenticitat de les dades. La majoria de les nostres propostes s’han inclòs a la versió final de l'estàndard, fusionant-les amb altres proposes (com amb el format del fitxer), demostrant la seva superioritat (com amb els mecanismes de seguretat), i fins i tot sent acceptades directament (com amb les regles de privacitat)

Security strategies in genomic files

There are new mechanisms to sequence and process the genomic code, discovering thus diagnostic tools and treatments. The file for a sequenced genome can reach hundreds of gigabytes. Thus, for further studies, we need new means to compress the information and a standardized representation to simplify the development of new tools. The ISO standardization group MPEG has used its expertise in compressing multimedia content to compress genomic information and develop its ´MPEG-G standard’. Given the sensitivity of the data, security is a major identified requirement. This thesis proposes novel technologies that assure the security of both the sequenced data and its metadata. We define a container-based file format to group data, metadata, and security information at the syntactical level. It includes new features like grouping multiple results in a same file to simplify the transport of whole studies. We use the granularity of the encoder’s output to enhance security. The information is represented in units, each dedicated to a specific region of the genome, which allows to provide encryption and signature features on a region base. We analyze the trade-off between security and an even more fine-grained approach and prove that apparently secure settings can be insecure: if the file creator may encrypt only specific elements of a unit, cross-checking unencrypted information permits to infer encrypted content. Most of the proposals for MPEG-G coming from other research groups and companies focused on data compression and representation. However, the need was recognized to find a solution for metadata encoding. Our proposal was included in the standard: an XML-based solution, separated in a core specification and extensions. It permits to adapt the metadata schema to the different genomic repositories' frameworks, without importing requirements from one framework to another. To simplify the handling of the resulting metadata, we define profiles, i.e. lists of extensions that must be present in a given framework. We use XML signature and XML encryption for metadata security. The MPEG requirements also concern access rules. Our privacy solutions limit the range of persons with access and we propose access rules represented with XACML to convey under which circumstances a user is granted access to a specific action among the ones specified in MPEG-G's API, e.g. filtering data by attributes. We also specify algorithms to combine multiple rules by defining default behaviors and exceptions. The standard’s security mechanisms protect the information only during transport and access. Once the data is obtained, the user could publish it. In order to identify leakers, we propose an algorithm that generates unique, virtually undetectable variations. Our solution is novel as the marking can be undone (and the utility of the data preserved) if the corresponding secret key is revealed. We also show how to combine multiple secret keys to avoid collusion. The API retained for MPEG-G considers search criteria not present in the indexing tables, which highlights shortcomings. Based on the proposed MPEG-G API we have developed a solution. It is based on a collaboration framework where the different users' needs and the patient's privacy settings result in a purpose-built file format that optimizes query times and provides privacy and authenticity on the patient-defined genomic regions. The encrypted output units are created and indexed to optimize query times and avoid rarely used indexing fields. Our approach resolves the shortcomings of MPEG-G's indexing strategy. We have submitted our technologies to the MPEG standardization committee. Many have been included in the final standard, via merging with other proposals (e.g. file format), discussion (e.g. security mechanisms), or direct acceptance (e.g. privacy rules).Hi han nous mètodes per la seqüenciació i el processament del codi genòmic, permetent descobrir eines de diagnòstic i tractaments en l’àmbit mèdic. El resultat de la seqüenciació d’un genoma es representa en un fitxer, que pot ocupar centenars de gigabytes. Degut a això, hi ha una necessitat d’una representació estandarditzada on la informació és comprimida. Dins de la ISO, el grup MPEG ha fet servir la seva experiència en compressió de dades multimèdia per comprimir dades genòmiques i desenvolupar l'estàndard MPEG-G, sent la seguretat un dels requeriments principals. L'objectiu de la tesi és garantir aquesta seguretat (encriptant, firmant i definint regles d¿ accés) tan per les dades seqüenciades com per les seves metadades. El primer pas és definir com transportar les dades, metadades i paràmetres de seguretat. Especifiquem un format de fitxer basat en contenidors per tal d'agrupar aquets elements a nivell sintàctic. La nostra solució proposa noves funcionalitats com agrupar múltiples resultats en un mateix fitxer. Pel que fa la seguretat de dades, la nostra proposta utilitza les propietats de la sortida del codificador. Aquesta sortida és estructurada en unitats, cadascuna dedicada a una regió concreta del genoma, permetent una encriptació i firma de dades específica a la unitat. Analitzem el compromís entre seguretat i un enfocament de gra més fi demostrant que configuracions aparentment vàlides poden no ser-ho: si es permet encriptar sols certes sub-unitats d'informació, creuant els continguts no encriptats, podem inferir el contingut encriptat. Quant a metadades, proposem una solució basada en XML separada en una especificació bàsica i en extensions. Podem adaptar l'esquema de metadades als diferents marcs de repositoris genòmics, sense imposar requeriments d’un marc a un altre. Per simplificar l'ús, plantegem la definició de perfils, és a dir, una llista de les extensions que han de ser present per un marc concret. Fem servir firmes XML i encriptació XML per implementar la seguretat de les metadades. Les nostres solucions per la privacitat limiten qui té accés a les dades, però no en limita l’ús. Proposem regles d’accés representades amb XACML per indicar en quines circumstàncies un usuari té dret d'executar una de les accions especificades a l'API de MPEG-G (per exemple, filtrar les dades per atributs). Presentem algoritmes per combinar regles, per tal de poder definir casos per defecte i excepcions. Els mecanismes de seguretat de MPEG-G protegeixen la informació durant el transport i l'accés. Una vegada l’usuari ha accedit a les dades, les podria publicar. Per tal d'identificar qui és l'origen del filtratge de dades, proposem un algoritme que genera modificacions úniques i virtualment no detectables. La nostra solució és pionera, ja que els canvis es poden desfer si el secret corresponent és publicat. Per tant, la utilitat de les dades és mantinguda. Demostrem que combinant varis secrets, podem evitar col·lusions. L'API seleccionada per MPEG-G, considera criteris de cerca que no són presents en les taules d’indexació. Basant-nos en aquesta API, hem desenvolupat una solució. És basada en un marc de col·laboració, on la combinació de les necessitats dels diferents usuaris i els requeriments de privacitat del pacient, es combinen en una representació ad-hoc que optimitza temps d’accessos tot i garantint la privacitat i autenticitat de les dades. La majoria de les nostres propostes s’han inclòs a la versió final de l'estàndard, fusionant-les amb altres proposes (com amb el format del fitxer), demostrant la seva superioritat (com amb els mecanismes de seguretat), i fins i tot sent acceptades directament (com amb les regles de privacitat)

Security strategies in genomic files

There are new mechanisms to sequence and process the genomic code, discovering thus diagnostic tools and treatments. The file for a sequenced genome can reach hundreds of gigabytes. Thus, for further studies, we need new means to compress the information and a standardized representation to simplify the development of new tools. The ISO standardization group MPEG has used its expertise in compressing multimedia content to compress genomic information and develop its ´MPEG-G standard’. Given the sensitivity of the data, security is a major identified requirement. This thesis proposes novel technologies that assure the security of both the sequenced data and its metadata. We define a container-based file format to group data, metadata, and security information at the syntactical level. It includes new features like grouping multiple results in a same file to simplify the transport of whole studies. We use the granularity of the encoder’s output to enhance security. The information is represented in units, each dedicated to a specific region of the genome, which allows to provide encryption and signature features on a region base. We analyze the trade-off between security and an even more fine-grained approach and prove that apparently secure settings can be insecure: if the file creator may encrypt only specific elements of a unit, cross-checking unencrypted information permits to infer encrypted content. Most of the proposals for MPEG-G coming from other research groups and companies focused on data compression and representation. However, the need was recognized to find a solution for metadata encoding. Our proposal was included in the standard: an XML-based solution, separated in a core specification and extensions. It permits to adapt the metadata schema to the different genomic repositories' frameworks, without importing requirements from one framework to another. To simplify the handling of the resulting metadata, we define profiles, i.e. lists of extensions that must be present in a given framework. We use XML signature and XML encryption for metadata security. The MPEG requirements also concern access rules. Our privacy solutions limit the range of persons with access and we propose access rules represented with XACML to convey under which circumstances a user is granted access to a specific action among the ones specified in MPEG-G's API, e.g. filtering data by attributes. We also specify algorithms to combine multiple rules by defining default behaviors and exceptions. The standard’s security mechanisms protect the information only during transport and access. Once the data is obtained, the user could publish it. In order to identify leakers, we propose an algorithm that generates unique, virtually undetectable variations. Our solution is novel as the marking can be undone (and the utility of the data preserved) if the corresponding secret key is revealed. We also show how to combine multiple secret keys to avoid collusion. The API retained for MPEG-G considers search criteria not present in the indexing tables, which highlights shortcomings. Based on the proposed MPEG-G API we have developed a solution. It is based on a collaboration framework where the different users' needs and the patient's privacy settings result in a purpose-built file format that optimizes query times and provides privacy and authenticity on the patient-defined genomic regions. The encrypted output units are created and indexed to optimize query times and avoid rarely used indexing fields. Our approach resolves the shortcomings of MPEG-G's indexing strategy. We have submitted our technologies to the MPEG standardization committee. Many have been included in the final standard, via merging with other proposals (e.g. file format), discussion (e.g. security mechanisms), or direct acceptance (e.g. privacy rules).Hi han nous mètodes per la seqüenciació i el processament del codi genòmic, permetent descobrir eines de diagnòstic i tractaments en l’àmbit mèdic. El resultat de la seqüenciació d’un genoma es representa en un fitxer, que pot ocupar centenars de gigabytes. Degut a això, hi ha una necessitat d’una representació estandarditzada on la informació és comprimida. Dins de la ISO, el grup MPEG ha fet servir la seva experiència en compressió de dades multimèdia per comprimir dades genòmiques i desenvolupar l'estàndard MPEG-G, sent la seguretat un dels requeriments principals. L'objectiu de la tesi és garantir aquesta seguretat (encriptant, firmant i definint regles d¿ accés) tan per les dades seqüenciades com per les seves metadades. El primer pas és definir com transportar les dades, metadades i paràmetres de seguretat. Especifiquem un format de fitxer basat en contenidors per tal d'agrupar aquets elements a nivell sintàctic. La nostra solució proposa noves funcionalitats com agrupar múltiples resultats en un mateix fitxer. Pel que fa la seguretat de dades, la nostra proposta utilitza les propietats de la sortida del codificador. Aquesta sortida és estructurada en unitats, cadascuna dedicada a una regió concreta del genoma, permetent una encriptació i firma de dades específica a la unitat. Analitzem el compromís entre seguretat i un enfocament de gra més fi demostrant que configuracions aparentment vàlides poden no ser-ho: si es permet encriptar sols certes sub-unitats d'informació, creuant els continguts no encriptats, podem inferir el contingut encriptat. Quant a metadades, proposem una solució basada en XML separada en una especificació bàsica i en extensions. Podem adaptar l'esquema de metadades als diferents marcs de repositoris genòmics, sense imposar requeriments d’un marc a un altre. Per simplificar l'ús, plantegem la definició de perfils, és a dir, una llista de les extensions que han de ser present per un marc concret. Fem servir firmes XML i encriptació XML per implementar la seguretat de les metadades. Les nostres solucions per la privacitat limiten qui té accés a les dades, però no en limita l’ús. Proposem regles d’accés representades amb XACML per indicar en quines circumstàncies un usuari té dret d'executar una de les accions especificades a l'API de MPEG-G (per exemple, filtrar les dades per atributs). Presentem algoritmes per combinar regles, per tal de poder definir casos per defecte i excepcions. Els mecanismes de seguretat de MPEG-G protegeixen la informació durant el transport i l'accés. Una vegada l’usuari ha accedit a les dades, les podria publicar. Per tal d'identificar qui és l'origen del filtratge de dades, proposem un algoritme que genera modificacions úniques i virtualment no detectables. La nostra solució és pionera, ja que els canvis es poden desfer si el secret corresponent és publicat. Per tant, la utilitat de les dades és mantinguda. Demostrem que combinant varis secrets, podem evitar col·lusions. L'API seleccionada per MPEG-G, considera criteris de cerca que no són presents en les taules d’indexació. Basant-nos en aquesta API, hem desenvolupat una solució. És basada en un marc de col·laboració, on la combinació de les necessitats dels diferents usuaris i els requeriments de privacitat del pacient, es combinen en una representació ad-hoc que optimitza temps d’accessos tot i garantint la privacitat i autenticitat de les dades. La majoria de les nostres propostes s’han inclòs a la versió final de l'estàndard, fusionant-les amb altres proposes (com amb el format del fitxer), demostrant la seva superioritat (com amb els mecanismes de seguretat), i fins i tot sent acceptades directament (com amb les regles de privacitat).Postprint (published version

Tatouage du flux compressé MPEG-4 AVC

La présente thèse aborde le sujet de tatouage du flux MPEG-4 AVC sur ses deux volets théoriques et applicatifs en considérant deux domaines applicatifs à savoir la protection du droit d auteur et la vérification de l'intégrité du contenu. Du point de vue théorique, le principal enjeu est de développer un cadre de tatouage unitaire en mesure de servir les deux applications mentionnées ci-dessus. Du point de vue méthodologique, le défi consiste à instancier ce cadre théorique pour servir les applications visées. La première contribution principale consiste à définir un cadre théorique pour le tatouage multi symboles à base de modulation d index de quantification (m-QIM). La règle d insertion QIM a été généralisée du cas binaire au cas multi-symboles et la règle de détection optimale (minimisant la probabilité d erreur à la détection en condition du bruit blanc, additif et gaussien) a été établie. Il est ainsi démontré que la quantité d information insérée peut être augmentée par un facteur de log2m tout en gardant les mêmes contraintes de robustesse et de transparence. Une quantité d information de 150 bits par minutes, soit environ 20 fois plus grande que la limite imposée par la norme DCI est obtenue. La deuxième contribution consiste à spécifier une opération de prétraitement qui permet d éliminer les impactes du phénomène du drift (propagation de la distorsion) dans le flux compressé MPEG-4 AVC. D abord, le problème a été formalisé algébriquement en se basant sur les expressions analytiques des opérations d encodage. Ensuite, le problème a été résolu sous la contrainte de prévention du drift. Une amélioration de la transparence avec des gains de 2 dB en PSNR est obtenueThe present thesis addresses the MPEG-4 AVC stream watermarking and considers two theoretical and applicative challenges, namely ownership protection and content integrity verification.From the theoretical point of view, the thesis main challenge is to develop a unitary watermarking framework (insertion/detection) able to serve the two above mentioned applications in the compressed domain. From the methodological point of view, the challenge is to instantiate this theoretical framework for serving the targeted applications. The thesis first main contribution consists in building the theoretical framework for the multi symbol watermarking based on quantization index modulation (m-QIM). The insertion rule is analytically designed by extending the binary QIM rule. The detection rule is optimized so as to ensure minimal probability of error under additive white Gaussian noise distributed attacks. It is thus demonstrated that the data payload can be increased by a factor of log2m, for prescribed transparency and additive Gaussian noise power. A data payload of 150 bits per minute, i.e. about 20 times larger than the limit imposed by the DCI standard, is obtained. The thesis second main theoretical contribution consists in specifying a preprocessing MPEG-4 AVC shaping operation which can eliminate the intra-frame drift effect. The drift represents the distortion spread in the compressed stream related to the MPEG encoding paradigm. In this respect, the drift distortion propagation problem in MPEG-4 AVC is algebraically expressed and the corresponding equations system is solved under drift-free constraints. The drift-free shaping results in gain in transparency of 2 dB in PSNREVRY-INT (912282302) / SudocSudocFranceF

Digital Watermarking for Verification of Perception-based Integrity of Audio Data

In certain application fields digital audio recordings contain sensitive content. Examples are historical archival material in public archives that preserve our cultural heritage, or digital evidence in the context of law enforcement and civil proceedings. Because of the powerful capabilities of modern editing tools for multimedia such material is vulnerable to doctoring of the content and forgery of its origin with malicious intent. Also inadvertent data modification and mistaken origin can be caused by human error. Hence, the credibility and provenience in terms of an unadulterated and genuine state of such audio content and the confidence about its origin are critical factors. To address this issue, this PhD thesis proposes a mechanism for verifying the integrity and authenticity of digital sound recordings. It is designed and implemented to be insensitive to common post-processing operations of the audio data that influence the subjective acoustic perception only marginally (if at all). Examples of such operations include lossy compression that maintains a high sound quality of the audio media, or lossless format conversions. It is the objective to avoid de facto false alarms that would be expectedly observable in standard crypto-based authentication protocols in the presence of these legitimate post-processing. For achieving this, a feasible combination of the techniques of digital watermarking and audio-specific hashing is investigated. At first, a suitable secret-key dependent audio hashing algorithm is developed. It incorporates and enhances so-called audio fingerprinting technology from the state of the art in contentbased audio identification. The presented algorithm (denoted as ”rMAC” message authentication code) allows ”perception-based” verification of integrity. This means classifying integrity breaches as such not before they become audible. As another objective, this rMAC is embedded and stored silently inside the audio media by means of audio watermarking technology. This approach allows maintaining the authentication code across the above-mentioned admissible post-processing operations and making it available for integrity verification at a later date. For this, an existent secret-key ependent audio watermarking algorithm is used and enhanced in this thesis work. To some extent, the dependency of the rMAC and of the watermarking processing from a secret key also allows authenticating the origin of a protected audio. To elaborate on this security aspect, this work also estimates the brute-force efforts of an adversary attacking this combined rMAC-watermarking approach. The experimental results show that the proposed method provides a good distinction and classification performance of authentic versus doctored audio content. It also allows the temporal localization of audible data modification within a protected audio file. The experimental evaluation finally provides recommendations about technical configuration settings of the combined watermarking-hashing approach. Beyond the main topic of perception-based data integrity and data authenticity for audio, this PhD work provides new general findings in the fields of audio fingerprinting and digital watermarking. The main contributions of this PhD were published and presented mainly at conferences about multimedia security. These publications were cited by a number of other authors and hence had some impact on their works

A digital signature and watermarking based authentication system for JPEG2000 images

In this thesis, digital signature based authentication system was introduced, which is able to protect JPEG2000 images in different flavors, including fragile authentication and semi-fragile authentication. The fragile authentication is to protect the image at code-stream level, and the semi-fragile is to protect the image at the content level. The semi-fragile can be further classified into lossy and lossless authentication. With lossless authentication, the original image can be recovered after verification. The lossless authentication and the new image compression standard, JPEG2000 is mainly discussed in this thesis

Axmedis 2005

The AXMEDIS conference aims to promote discussions and interactions among researchers, practitioners, developers and users of tools, technology transfer experts, and project managers, to bring together a variety of participants. The conference focuses on the challenges in the cross-media domain (which include production, protection, management, representation, formats, aggregation, workflow, distribution, business and transaction models), and the integration of content management systems and distribution chains, with particular emphasis on cost reduction and effective solutions for complex cross-domain problems

New Digital Audio Watermarking Algorithms for Copyright Protection

This thesis investigates the development of digital audio watermarking in addressing issues such as copyright protection. Over the past two decades, many digital watermarking algorithms have been developed, each with its own advantages and disadvantages. The main aim of this thesis was to develop a new watermarking algorithm within an existing Fast Fourier Transform framework. This resulted in the development of a Complex Spectrum Phase Evolution based watermarking algorithm. In this new implementation, the embedding positions were generated dynamically thereby rendering it more difficult for an attacker to remove, and watermark information was embedded by manipulation of the spectral components in the time domain thereby reducing any audible distortion. Further improvements were attained when the embedding criteria was based on bin location comparison instead of magnitude, thereby rendering it more robust against those attacks that interfere with the spectral magnitudes. However, it was discovered that this new audio watermarking algorithm has some disadvantages such as a relatively low capacity and a non-consistent robustness for different audio files. Therefore, a further aim of this thesis was to improve the algorithm from a different perspective. Improvements were investigated using an Singular Value Decomposition framework wherein a novel observation was discovered. Furthermore, a psychoacoustic model was incorporated to suppress any audible distortion. This resulted in a watermarking algorithm which achieved a higher capacity and a more consistent robustness. The overall result was that two new digital audio watermarking algorithms were developed which were complementary in their performance thereby opening more opportunities for further research