{"publication_status":"published","main_file_link":[{"open_access":"1","url":"https://eprint.iacr.org/2016/279.pdf"}],"author":[{"id":"40297222-F248-11E8-B48F-1D18A9856A87","full_name":"Abusalah, Hamza M","last_name":"Abusalah","first_name":"Hamza M"},{"id":"46B4C3EE-F248-11E8-B48F-1D18A9856A87","last_name":"Fuchsbauer","first_name":"Georg","full_name":"Fuchsbauer, Georg"}],"publist_id":"6098","date_created":"2018-12-11T11:50:52Z","_id":"1235","ec_funded":1,"project":[{"call_identifier":"FP7","name":"Provable Security for Physical Cryptography","_id":"258C570E-B435-11E9-9278-68D0E5697425","grant_number":"259668"},{"_id":"258AA5B2-B435-11E9-9278-68D0E5697425","name":"Teaching Old Crypto New Tricks","call_identifier":"H2020","grant_number":"682815"}],"acknowledgement":"H. Abusalah—Research supported by the European Research Council, ERC starting grant (259668-PSPC) and ERC consolidator grant (682815 - TOCNeT).","language":[{"iso":"eng"}],"year":"2016","type":"conference","page":"445 - 463","title":"Constrained PRFs for unbounded inputs with short keys","citation":{"short":"H.M. Abusalah, G. Fuchsbauer, in:, Springer, 2016, pp. 445–463.","apa":"Abusalah, H. M., &#38; Fuchsbauer, G. (2016). Constrained PRFs for unbounded inputs with short keys (Vol. 9696, pp. 445–463). Presented at the ACNS: Applied Cryptography and Network Security, Guildford, UK: Springer. <a href=\"https://doi.org/10.1007/978-3-319-39555-5_24\">https://doi.org/10.1007/978-3-319-39555-5_24</a>","ama":"Abusalah HM, Fuchsbauer G. Constrained PRFs for unbounded inputs with short keys. In: Vol 9696. Springer; 2016:445-463. doi:<a href=\"https://doi.org/10.1007/978-3-319-39555-5_24\">10.1007/978-3-319-39555-5_24</a>","chicago":"Abusalah, Hamza M, and Georg Fuchsbauer. “Constrained PRFs for Unbounded Inputs with Short Keys,” 9696:445–63. Springer, 2016. <a href=\"https://doi.org/10.1007/978-3-319-39555-5_24\">https://doi.org/10.1007/978-3-319-39555-5_24</a>.","mla":"Abusalah, Hamza M., and Georg Fuchsbauer. <i>Constrained PRFs for Unbounded Inputs with Short Keys</i>. Vol. 9696, Springer, 2016, pp. 445–63, doi:<a href=\"https://doi.org/10.1007/978-3-319-39555-5_24\">10.1007/978-3-319-39555-5_24</a>.","ista":"Abusalah HM, Fuchsbauer G. 2016. Constrained PRFs for unbounded inputs with short keys. ACNS: Applied Cryptography and Network Security, LNCS, vol. 9696, 445–463.","ieee":"H. M. Abusalah and G. Fuchsbauer, “Constrained PRFs for unbounded inputs with short keys,” presented at the ACNS: Applied Cryptography and Network Security, Guildford, UK, 2016, vol. 9696, pp. 445–463."},"status":"public","department":[{"_id":"KrPi"}],"date_published":"2016-01-01T00:00:00Z","quality_controlled":"1","month":"01","alternative_title":["LNCS"],"doi":"10.1007/978-3-319-39555-5_24","conference":{"end_date":"2016-06-22","start_date":"2016-06-19","name":"ACNS: Applied Cryptography and Network Security","location":"Guildford, UK"},"scopus_import":1,"date_updated":"2023-09-07T12:30:22Z","intvolume":"      9696","user_id":"3E5EF7F0-F248-11E8-B48F-1D18A9856A87","day":"01","volume":9696,"oa_version":"Submitted Version","related_material":{"record":[{"status":"public","relation":"dissertation_contains","id":"83"}]},"publisher":"Springer","oa":1,"abstract":[{"lang":"eng","text":"A constrained pseudorandom function (CPRF) F: K×X → Y for a family T of subsets of χ is a function where for any key k ∈ K and set S ∈ T one can efficiently compute a short constrained key kS, which allows to evaluate F(k, ·) on all inputs x ∈ S, while the outputs on all inputs x /∈ S look random even given kS. Abusalah et al. recently constructed the first constrained PRF for inputs of arbitrary length whose sets S are decided by Turing machines. They use their CPRF to build broadcast encryption and the first ID-based non-interactive key exchange for an unbounded number of users. Their constrained keys are obfuscated circuits and are therefore large. In this work we drastically reduce the key size and define a constrained key for a Turing machine M as a short signature on M. For this, we introduce a new signature primitive with constrained signing keys that let one only sign certain messages, while forging a signature on others is hard even when knowing the coins for key generation."}]}