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public:research:conferences:wistp2015 [2015-09-03 13:42] – Page moved from public:research:confnotes:wistp2015 to public:research:conferences:wistp2015 mukrop | public:research:conferences:wistp2015 [2024-01-17 15:39] (current) – removed xjancar | ||
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- | ====== Conference notes: WISTP2015, TRUST2015 ====== | ||
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- | * TRUST 2015: http:// | ||
- | * WISTP 2015: http:// | ||
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- | **Paper: Tassos Dimitriou and Ioannis Krontiris, Privacy-respecting Auctions as Incentive Mechanisms in Mobile Crowd Sensing** | ||
- | * sensing data via user mobile phones | ||
- | * motivation for users - micropayments | ||
- | * to keep payments low, auction is used | ||
- | * user generates keypair, encrypt bid under public key, then publish private key -> winner is selected by report server | ||
- | * how to provide payments to anonymous (during auction) users? | ||
- | * payment made via tokens later payed by bank (e-cash, problem with colluding report server and bank -> reveal user identity) | ||
- | * payment made via blind signatures | ||
- | * nice attack from audience: user selects N different pseudonyms, set very low bidding price => wins bids | ||
- | * ? can we use bitcoin for that? - can be used | ||
- | * ? autonomous execution without user interaction? | ||
- | * ? is report server trusted entity? - trusted to select winner and pay | ||
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- | **Paper: Alejandro Calleja, Pedro Peris-Lopez and Juan E. Tapiador, Electrical Heart Signals can be Monitored from the Moon: Security Implications for IPI-based Protocols** | ||
- | * Implantable medical devices | ||
- | * similar to RFID, except need for emergency mode - in problems, direct access from medstaff is possible | ||
- | * wireless connectivity used for remote monitoring | ||
- | * use of biosignals to authenticate -> used in emergency (have access to ECG anyway) - already published paper | ||
- | * this paper: how well we can estimate ECG using webcam (malware on computer)? | ||
- | * practical experiment PPG sensor (true value) + webcam measurement -> similarity measured | ||
- | * results: ~60% similarity (50% is baseline random guess) | ||
- | * dynamic quantifier - almost no correlation (doesn' | ||
- | * scalar quantifier - 60-95% success (avg 70% similarity) | ||
- | * ? what features were extracted from webcam picture? Movement of nose. But very noisy data, better cam cam improve (but lost of attacker vector with malware-controled webcam) | ||
- | * ? Why not use fingerprint as additional factor to authenticate? | ||
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- | **Paper: Neyire Deniz Sarier, Private Minutia-based Fingerprint Matching** | ||
- | * biometrics IBE approach, multimodal biometrics | ||
- | * inherent noise in biometric samples -> error-tolerant schemes necessary | ||
- | * removal of Random oracle model (reason: if hash function is used in ROM, then scheme is insecure (generic result?)) | ||
- | * naive model for PSI (send multiple hashes of measured biometrics - vulnerable to pre-image recovery in case of low-entropy inputs), DH-base PSI-CA (Enhacing privacy and trust in electonic communities, | ||
- | * Faster private set intersection base on OT extension, usenix 2014 | ||
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- | **Paper: David Jaeger, Amir Azodi, Feng Cheng and Christoph Meinel, Normalizing Security Events with a Hierarchical Knowledge Base** | ||
- | * trying to improve situation with system logs normalization | ||
- | * then correlate events for security incidents | ||
- | * unified extractor and convertor into same log structure | ||
- | * speed 37000 events/sec (8 cores) - usable for big company | ||
- | * ? implementation of compiler for regular expressions that compiles many RE together and then executed faster then every RE one-by-one. | ||
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- | **Paper: Konstantinos Fysarakis, Charalampos Konstantourakis, | ||
- | * XACML - extensible acces control markup language | ||
- | * DPWS protocol (UPnP for large networks) used to transfer message of events, server decides based on policy | ||
- | * implementation on Android tablet | ||
- | * Register device inside system, set own policies for usage, smart device is sensor providing data | ||
- | * intended for e-health scenario (combination of requirements from multiple parties) | ||
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- | **Invited talk: Formal definitions in crypto** | ||
- | * inputs and outputs of algorithm | ||
- | * security goal and thread model | ||
- | * security game: challenger and attacker -> asks attacker to breach security goal | ||
- | * lack of unconditionally secure schemes => what are assumptions? | ||
- | * proofs of security. Usually in form of reduction scheme -> assumption or scheme -> known hard problem | ||
- | * proof then usually proof by contradiction: | ||
- | * semantic security (!even single bit, hard to work with) -> ciphetext indistinguishability (Goldwasser, | ||
- | * ciphetetxt-only, | ||
- | * IND-CPA: attacker is supplying two messages (crafted by an attacker) | ||
- | * which IND-xxx is used? Depending on what you can (as an author of scheme) prove :) | ||
- | * only in 2010: What happens if I will use private key on message not encrypted by my public key? -> Robustness property (weak and strong) | ||
- | * overall message: many state of the art protocols are insecure, usually because of imprecise of missing proper model assumptions | ||
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- | **Keynote: Anand Rajan, " | ||
- | * Schoda search engine for iot | ||
- | * device will last probably longer then PC -> implications for security | ||
- | * managebility is problem | ||
- | * just enough security for every endpoint as resources as limited (but hard to establish what is enough when device will be planted for 30 years) | ||
- | * devices often operates in groups | ||
- | * usability is critical (no manual configuration, | ||
- | * how to connect (and discover) devices into group ?- what is right topology and mode of commmuication? | ||
- | * secure iot lifecycle: start secure, run secure, stay secure | ||
- | * problem of (security) updates | ||
- | * autodraha pro simulaci pohyblivych uzlu a jen docasneho kontaktu | ||
- | * security needs to be cradle-to-grave - question: why only grave, repurposed chips -> reincarnation? | ||
- | * after time, some devices can start to be insecure (or owner is not sure) -> gray area of probabilistic trust - how to deal with partially compromised network? Can we use secrecy amplification protocols to reestablish trust again (our original idea of chain of trust amplification) | ||
- | * nice demo with car race hack to change speed of car - " | ||
- | * intel trusted execution for very small CPU (MCU) - " | ||
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- | **Paper: Hamed Nemati, Mads Dam and Roberto Guanciale. " | ||
- | * first formally verified design of direct pagging | ||
- | * custom slim implemlementation of direct paging, later formally verified | ||
- | * MMU virtualization, | ||
- | * selected slim configuration doable by formal verification | ||
- | * blocks are typed (L1/L2 page table, D) | ||
- | * minimal API activate, active, create, free table | ||
- | * refenrence counter | ||
- | * HOL4 theorem prover, extended | ||
- | * 5 bugs discovered during verification | ||
- | * Beagleboard platform to verify model (4529 LOC C + Assembly, 1500 LOC HOL4 model, 18700 LOC HOL4 proof - script for verifier) | ||
- | * overall efford: 19 person month to perform whole proof (!) | ||
- | * proof cannot be directly used to verify similar scenario (written directly for particular implementation) | ||
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- | **Paper: Sourav Bhattacharya, | ||
- | * target is to notify users with known unsafe webpages | ||
- | * based on crowsource rating | ||
- | * web of trust WoT (137mills users) | ||
- | * two categories for marking: trustwortiness, | ||
- | * browser extension | ||
- | * problem with coverage (WoT rating compared with Alexa top 1M) => still low coverage | ||
- | * research question: can we predict rating for unrated pages (based on content of rated pages?) | ||
- | * link-related links: take reputation from links target page is linking | ||
- | * problem: falsely linking good pages. Solved by taking just links with bad reputation | ||
- | * Topic Model-base features: ECDF, Latent xxx something | ||
- | * extracted features used for training later | ||
- | * performance evalution: 140000 webpages - 80k good, 60k bad, ground truth obatined from WOT | ||
- | * Random forest classifier | ||
- | * tech report: arxiv.org/ | ||
- | * ? bias behind rated pages? | ||
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- | **Paper: Analysis of usage patterns in Ripple protocolFrederik Armknecht, Ghassan Karame, Avikarsha Mandal, Franck Youssef and Erik Zenner. " | ||
- | * Distributed online payment | ||
- | * trust-based credit network | ||
- | * second largerst after bitcoin ($280), already signed with some banks | ||
- | * (Stellar network - similar concept) | ||
- | * public ledger for transactions, | ||
- | * comparison: photo, faster then bitcoin (<20 sec to commit transaction), | ||
- | * forking problem: two ledgers, for current Ripple settings, if 40% nodes will overlap with ledger validation, fork will ocur (doublespending...) | ||
- | * official statistics are probably skewed | ||
- | * a lot of artificial transaction not finished (only about 15% is real transcation) | ||
- | * most of the current accounts are inactive (might be theoretically many accounts for single person because of privacy, but unlikely) | ||
- | * ? inactive accounts - not used, different from validators | ||
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- | **Paper: Patrick Koeberl, Vinay Phegade, Anand Rajan, Thomas Schneider, Steffen Schulz and Maria Zhdanova. "Time to Rethink: Trust Brokerage using Trusted Execution Environments" | ||
- | * data exists in silos - lack of sharing | ||
- | * secure multiparty computations (many protocols over 30 years, but still lacks efficiency and requires custom tailoring from " | ||
- | * Data de-indentification - need to filter data and customize, tough privacy to uitility tradeoff | ||
- | * talk's approach: TEE-based Trest Brokerage | ||
- | * computing infrastructire based on trusted boot | ||
- | * uses Intel' | ||
- | * validation part TC is potential bottleneck (a lot of work focused on measurement, | ||
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- | **Paper: David Förster, Hans Löhr, Jan Zibuschka and Frank Kargl. " | ||
- | * vehicle to vehicle and vehicle to infrastructure communication | ||
- | * warnings for out of sight events (strong brakes of close, but not directly visible car) | ||
- | * authorization, | ||
- | * short-term certificates (20 per weaks - used for pseduonyms) | ||
- | * long-term certificate (for authentication and renew of certificates) | ||
- | * long-term certificate can be replaced by anononymous credentials | ||
- | * if vehicle is sending invalid messages, it is reported (by pseudonym X) and then certral point sends message to particular location - if you are X, please delete your current keys, you are folty -> targets invalid, but honest vehicle | ||
- | * enforcement via trusted component for intentionally malicious devices -> keys are stored in secure modules | ||
- | * but attacker can turn off device -> delete comand is issued every time device requires new certificate | ||
- | * another protection: keep-alive messages undistinguisable from delete command (turn off will not help) -> but problem with car outside reach of messages -> if device is blocked, one need to visit car manufacturer => jam car -> block car . Quite controversional defense | ||
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- | **Paper: Melanie Volkamer, Karen Renaud, Kristoffer Braun, Gamze Canova and Benjamin Reinheimer. Design and Field Evaluation of PassSec: Raising and Sustaining Web Surfer Risk Awareness** | ||
- | * PassSec - firefox extension to detect insecure websites | ||
- | * paper: mental model of user wrt security, automatic checks -> show additional warning in time relevant to expected mental model | ||
- | * field experiment -> 31 participants -> initially 60 (but these didn't replayed for questionarre) | ||
- | * problem: small test group | ||
- | * problem: the group statistics were not clear - is it average user? | ||
- | * problem: dropouts from study were not included in measurement (not even usage statistics from dropouts usage were presented - maybe not collected?) | ||
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- | **Paper: Rainer Urian and Liqun Chen. DAA-A: Direct Anonymous Attestation with Attributes** | ||
- | * based on TPM 2.0 specification | ||
- | * flexible use of existing standard to provide new class of protocols | ||
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