{"id":"https://openalex.org/W7143493512","doi":"https://doi.org/10.1109/tifs.2026.3678787","title":"PromptGuard: Soft Prompt-Guided Unsafe Content Moderation for Text-to-Image Models","display_name":"PromptGuard: Soft Prompt-Guided Unsafe Content Moderation for Text-to-Image Models","publication_year":2026,"publication_date":"2026-01-01","ids":{"openalex":"https://openalex.org/W7143493512","doi":"https://doi.org/10.1109/tifs.2026.3678787"},"language":null,"primary_location":{"id":"doi:10.1109/tifs.2026.3678787","is_oa":false,"landing_page_url":"https://doi.org/10.1109/tifs.2026.3678787","pdf_url":null,"source":{"id":"https://openalex.org/S61310614","display_name":"IEEE Transactions on Information Forensics and Security","issn_l":"1556-6013","issn":["1556-6013","1556-6021"],"is_oa":false,"is_in_doaj":false,"is_core":true,"host_organization":"https://openalex.org/P4310319808","host_organization_name":"Institute of Electrical and Electronics Engineers","host_organization_lineage":["https://openalex.org/P4310319808"],"host_organization_lineage_names":["Institute of Electrical and Electronics Engineers"],"type":"journal"},"license":null,"license_id":null,"version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"IEEE Transactions on Information Forensics and Security","raw_type":"journal-article"},"type":"article","indexed_in":["crossref"],"open_access":{"is_oa":false,"oa_status":"closed","oa_url":null,"any_repository_has_fulltext":false},"authorships":[{"author_position":"first","author":{"id":"https://openalex.org/A5088152772","display_name":"Lingzhi Yuan","orcid":"https://orcid.org/0000-0001-5004-494X"},"institutions":[{"id":"https://openalex.org/I66946132","display_name":"University of Maryland, College Park","ror":"https://ror.org/047s2c258","country_code":"US","type":"education","lineage":["https://openalex.org/I66946132"]}],"countries":["US"],"is_corresponding":false,"raw_author_name":"Lingzhi Yuan","raw_affiliation_strings":["Department of Computer Science, University of Maryland, College Park, MD, USA"],"raw_orcid":"https://orcid.org/0009-0009-0376-6574","affiliations":[{"raw_affiliation_string":"Department of Computer Science, University of Maryland, College Park, MD, USA","institution_ids":["https://openalex.org/I66946132"]}]},{"author_position":"middle","author":{"id":"https://openalex.org/A5012208102","display_name":"Xinfeng Li","orcid":null},"institutions":[{"id":"https://openalex.org/I172675005","display_name":"Nanyang Technological University","ror":"https://ror.org/02e7b5302","country_code":"SG","type":"education","lineage":["https://openalex.org/I172675005"]}],"countries":["SG"],"is_corresponding":false,"raw_author_name":"Xinfeng Li","raw_affiliation_strings":["College of Computing and Data Science, Nanyang Technological University, Jurong West, Singapore"],"raw_orcid":"https://orcid.org/0000-0002-9686-4369","affiliations":[{"raw_affiliation_string":"College of Computing and Data Science, Nanyang Technological University, Jurong West, Singapore","institution_ids":["https://openalex.org/I172675005"]}]},{"author_position":"middle","author":{"id":"https://openalex.org/A5004007883","display_name":"Chejian Xu","orcid":"https://orcid.org/0009-0009-7598-639X"},"institutions":[{"id":"https://openalex.org/I157725225","display_name":"University of Illinois Urbana-Champaign","ror":"https://ror.org/047426m28","country_code":"US","type":"education","lineage":["https://openalex.org/I157725225"]}],"countries":["US"],"is_corresponding":false,"raw_author_name":"Chejian Xu","raw_affiliation_strings":["Siebel School of Computing and Data Science, University of Illinois Urbana&#x2013;Champaign, Urbana, IL, USA"],"raw_orcid":"https://orcid.org/0009-0009-7598-639X","affiliations":[{"raw_affiliation_string":"Siebel School of Computing and Data Science, University of Illinois Urbana&#x2013;Champaign, Urbana, IL, USA","institution_ids":["https://openalex.org/I157725225"]}]},{"author_position":"middle","author":{"id":"https://openalex.org/A5014842586","display_name":"Guanhong Tao","orcid":"https://orcid.org/0000-0002-4701-1327"},"institutions":[{"id":"https://openalex.org/I223532165","display_name":"University of Utah","ror":"https://ror.org/03r0ha626","country_code":"US","type":"education","lineage":["https://openalex.org/I223532165"]}],"countries":["US"],"is_corresponding":false,"raw_author_name":"Guanhong Tao","raw_affiliation_strings":["Kahlert School of Computing, The University of Utah, Salt Lake City, UT, USA"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Kahlert School of Computing, The University of Utah, Salt Lake City, UT, USA","institution_ids":["https://openalex.org/I223532165"]}]},{"author_position":"middle","author":{"id":"https://openalex.org/A5084784341","display_name":"Xiaojun Jia","orcid":"https://orcid.org/0000-0002-2018-9344"},"institutions":[{"id":"https://openalex.org/I172675005","display_name":"Nanyang Technological University","ror":"https://ror.org/02e7b5302","country_code":"SG","type":"education","lineage":["https://openalex.org/I172675005"]}],"countries":["SG"],"is_corresponding":false,"raw_author_name":"Xiaojun Jia","raw_affiliation_strings":["College of Computing and Data Science, Nanyang Technological University, Jurong West, Singapore"],"raw_orcid":"https://orcid.org/0000-0002-2018-9344","affiliations":[{"raw_affiliation_string":"College of Computing and Data Science, Nanyang Technological University, Jurong West, Singapore","institution_ids":["https://openalex.org/I172675005"]}]},{"author_position":"middle","author":{"id":"https://openalex.org/A5125734452","display_name":"Yihao Huang","orcid":null},"institutions":[{"id":"https://openalex.org/I172675005","display_name":"Nanyang Technological University","ror":"https://ror.org/02e7b5302","country_code":"SG","type":"education","lineage":["https://openalex.org/I172675005"]}],"countries":["SG"],"is_corresponding":false,"raw_author_name":"Yihao Huang","raw_affiliation_strings":["College of Computing and Data Science, Nanyang Technological University, Jurong West, Singapore"],"raw_orcid":"https://orcid.org/0000-0002-5784-770X","affiliations":[{"raw_affiliation_string":"College of Computing and Data Science, Nanyang Technological University, Jurong West, Singapore","institution_ids":["https://openalex.org/I172675005"]}]},{"author_position":"middle","author":{"id":"https://openalex.org/A5131253401","display_name":"Wei Dong","orcid":null},"institutions":[{"id":"https://openalex.org/I172675005","display_name":"Nanyang Technological University","ror":"https://ror.org/02e7b5302","country_code":"SG","type":"education","lineage":["https://openalex.org/I172675005"]}],"countries":["SG"],"is_corresponding":false,"raw_author_name":"Wei Dong","raw_affiliation_strings":["College of Computing and Data Science, Nanyang Technological University, Jurong West, Singapore"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"College of Computing and Data Science, Nanyang Technological University, Jurong West, Singapore","institution_ids":["https://openalex.org/I172675005"]}]},{"author_position":"middle","author":{"id":"https://openalex.org/A5100355692","display_name":"Yang Liu","orcid":"https://orcid.org/0000-0001-7300-9215"},"institutions":[{"id":"https://openalex.org/I172675005","display_name":"Nanyang Technological University","ror":"https://ror.org/02e7b5302","country_code":"SG","type":"education","lineage":["https://openalex.org/I172675005"]}],"countries":["SG"],"is_corresponding":false,"raw_author_name":"Yang Liu","raw_affiliation_strings":["College of Computing and Data Science, Nanyang Technological University, Jurong West, Singapore"],"raw_orcid":"https://orcid.org/0000-0001-7300-9215","affiliations":[{"raw_affiliation_string":"College of Computing and Data Science, Nanyang Technological University, Jurong West, Singapore","institution_ids":["https://openalex.org/I172675005"]}]},{"author_position":"last","author":{"id":"https://openalex.org/A5100374521","display_name":"Bo Li","orcid":"https://orcid.org/0000-0003-4186-4828"},"institutions":[{"id":"https://openalex.org/I157725225","display_name":"University of Illinois Urbana-Champaign","ror":"https://ror.org/047426m28","country_code":"US","type":"education","lineage":["https://openalex.org/I157725225"]}],"countries":["US"],"is_corresponding":false,"raw_author_name":"Bo Li","raw_affiliation_strings":["Siebel School of Computing and Data Science, University of Illinois Urbana&#x2013;Champaign, Urbana, IL, USA"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Siebel School of Computing and Data Science, University of Illinois Urbana&#x2013;Champaign, Urbana, IL, USA","institution_ids":["https://openalex.org/I157725225"]}]}],"institutions":[],"countries_distinct_count":2,"institutions_distinct_count":4,"corresponding_author_ids":[],"corresponding_institution_ids":[],"apc_list":{"value":2645,"currency":"USD","value_usd":2645},"apc_paid":null,"fwci":0.0,"has_fulltext":false,"cited_by_count":0,"citation_normalized_percentile":{"value":0.25978999,"is_in_top_1_percent":false,"is_in_top_10_percent":false},"cited_by_percentile_year":null,"biblio":{"volume":"21","issue":null,"first_page":"4051","last_page":"4061"},"is_retracted":false,"is_paratext":false,"is_xpac":false,"primary_topic":{"id":"https://openalex.org/T10775","display_name":"Generative Adversarial Networks and Image Synthesis","score":0.37929999828338623,"subfield":{"id":"https://openalex.org/subfields/1707","display_name":"Computer Vision and Pattern Recognition"},"field":{"id":"https://openalex.org/fields/17","display_name":"Computer Science"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},"topics":[{"id":"https://openalex.org/T10775","display_name":"Generative Adversarial Networks and Image Synthesis","score":0.37929999828338623,"subfield":{"id":"https://openalex.org/subfields/1707","display_name":"Computer Vision and Pattern Recognition"},"field":{"id":"https://openalex.org/fields/17","display_name":"Computer Science"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},{"id":"https://openalex.org/T11689","display_name":"Adversarial Robustness in Machine Learning","score":0.28299999237060547,"subfield":{"id":"https://openalex.org/subfields/1702","display_name":"Artificial Intelligence"},"field":{"id":"https://openalex.org/fields/17","display_name":"Computer Science"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},{"id":"https://openalex.org/T12262","display_name":"Hate Speech and Cyberbullying Detection","score":0.12139999866485596,"subfield":{"id":"https://openalex.org/subfields/1702","display_name":"Artificial Intelligence"},"field":{"id":"https://openalex.org/fields/17","display_name":"Computer Science"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}}],"keywords":[{"id":"https://openalex.org/keywords/moderation","display_name":"Moderation","score":0.5187000036239624},{"id":"https://openalex.org/keywords/relation","display_name":"Relation (database)","score":0.30790001153945923},{"id":"https://openalex.org/keywords/data-modeling","display_name":"Data modeling","score":0.2903999984264374},{"id":"https://openalex.org/keywords/electronic-mail","display_name":"Electronic mail","score":0.2556000053882599},{"id":"https://openalex.org/keywords/component","display_name":"Component (thermodynamics)","score":0.25519999861717224}],"concepts":[{"id":"https://openalex.org/C41008148","wikidata":"https://www.wikidata.org/wiki/Q21198","display_name":"Computer science","level":0,"score":0.6216999888420105},{"id":"https://openalex.org/C93225998","wikidata":"https://www.wikidata.org/wiki/Q1941972","display_name":"Moderation","level":2,"score":0.5187000036239624},{"id":"https://openalex.org/C38652104","wikidata":"https://www.wikidata.org/wiki/Q3510521","display_name":"Computer security","level":1,"score":0.3303999900817871},{"id":"https://openalex.org/C25343380","wikidata":"https://www.wikidata.org/wiki/Q277521","display_name":"Relation (database)","level":2,"score":0.30790001153945923},{"id":"https://openalex.org/C67186912","wikidata":"https://www.wikidata.org/wiki/Q367664","display_name":"Data modeling","level":2,"score":0.2903999984264374},{"id":"https://openalex.org/C56739046","wikidata":"https://www.wikidata.org/wiki/Q192060","display_name":"Knowledge management","level":1,"score":0.28369998931884766},{"id":"https://openalex.org/C108827166","wikidata":"https://www.wikidata.org/wiki/Q175975","display_name":"Internet privacy","level":1,"score":0.2761000096797943},{"id":"https://openalex.org/C3020028006","wikidata":"https://www.wikidata.org/wiki/Q9158","display_name":"Electronic mail","level":2,"score":0.2556000053882599},{"id":"https://openalex.org/C168167062","wikidata":"https://www.wikidata.org/wiki/Q1117970","display_name":"Component (thermodynamics)","level":2,"score":0.25519999861717224},{"id":"https://openalex.org/C107457646","wikidata":"https://www.wikidata.org/wiki/Q207434","display_name":"Human\u2013computer interaction","level":1,"score":0.2547999918460846},{"id":"https://openalex.org/C183322885","wikidata":"https://www.wikidata.org/wiki/Q17007702","display_name":"Context model","level":3,"score":0.2540999948978424},{"id":"https://openalex.org/C112930515","wikidata":"https://www.wikidata.org/wiki/Q4389547","display_name":"Risk analysis (engineering)","level":1,"score":0.25380000472068787},{"id":"https://openalex.org/C162446236","wikidata":"https://www.wikidata.org/wiki/Q653137","display_name":"Content analysis","level":2,"score":0.25380000472068787},{"id":"https://openalex.org/C2778152352","wikidata":"https://www.wikidata.org/wiki/Q5165061","display_name":"Content (measure theory)","level":2,"score":0.2515000104904175}],"mesh":[],"locations_count":1,"locations":[{"id":"doi:10.1109/tifs.2026.3678787","is_oa":false,"landing_page_url":"https://doi.org/10.1109/tifs.2026.3678787","pdf_url":null,"source":{"id":"https://openalex.org/S61310614","display_name":"IEEE Transactions on Information Forensics and Security","issn_l":"1556-6013","issn":["1556-6013","1556-6021"],"is_oa":false,"is_in_doaj":false,"is_core":true,"host_organization":"https://openalex.org/P4310319808","host_organization_name":"Institute of Electrical and Electronics Engineers","host_organization_lineage":["https://openalex.org/P4310319808"],"host_organization_lineage_names":["Institute of Electrical and Electronics Engineers"],"type":"journal"},"license":null,"license_id":null,"version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"IEEE Transactions on Information Forensics and Security","raw_type":"journal-article"}],"best_oa_location":null,"sustainable_development_goals":[],"awards":[],"funders":[{"id":"https://openalex.org/F4320320709","display_name":"National Research Foundation Singapore","ror":"https://ror.org/03cpyc314"}],"has_content":{"grobid_xml":false,"pdf":false},"content_urls":null,"referenced_works_count":21,"referenced_works":["https://openalex.org/W2068511562","https://openalex.org/W2161551760","https://openalex.org/W2896457183","https://openalex.org/W2952122856","https://openalex.org/W2962785568","https://openalex.org/W4205991051","https://openalex.org/W4211179769","https://openalex.org/W4312933868","https://openalex.org/W4386066536","https://openalex.org/W4388858734","https://openalex.org/W4390871724","https://openalex.org/W4394593019","https://openalex.org/W4394777948","https://openalex.org/W4401043113","https://openalex.org/W4402264152","https://openalex.org/W4402672042","https://openalex.org/W4402713133","https://openalex.org/W4403842422","https://openalex.org/W4408750013","https://openalex.org/W7133235460","https://openalex.org/W7133250524"],"related_works":[],"abstract_inverted_index":{"Recent":[0],"text-to-image":[1],"(T2I)":[2],"models":[3,17,62,70],"have":[4],"exhibited":[5],"remarkable":[6],"performance":[7],"in":[8,59],"generating":[9,23],"high-quality":[10,164],"images":[11],"from":[12,54],"text":[13],"descriptions.":[14],"However,":[15],"these":[16],"are":[18,209],"vulnerable":[19],"to":[20,83,200],"misuse,":[21],"particularly":[22],"not-safe-for-work":[24],"(NSFW)":[25],"content,":[26],"such":[27],"as":[28,91],"sexually":[29],"explicit,":[30],"violent,":[31],"political,":[32],"and":[33,131,142,187,202,207],"disturbing":[34],"images,":[35],"raising":[36],"serious":[37],"ethical":[38],"concerns.":[39],"In":[40],"this":[41],"work,":[42],"we":[43],"present":[44],"PromptGuard,":[45],"a":[46,72,85,134],"novel":[47],"content":[48,160,174],"moderation":[49,175],"technique":[50],"that":[51,89,155],"draws":[52],"inspiration":[53],"the":[55,97,120],"system":[56,94],"prompt":[57,88,95,106],"mechanism":[58],"large":[60],"language":[61],"(LLMs)":[63],"for":[64,75],"safety":[65,86,147],"alignment.":[66],"Unlike":[67],"LLMs,":[68],"T2I":[69,98],"lack":[71],"direct":[73],"interface":[74],"enforcing":[76],"behavioral":[77],"guidelines.":[78],"Our":[79,205],"key":[80],"idea":[81],"is":[82],"optimize":[84],"soft":[87,105,140],"functions":[90],"an":[92,194],"implicit":[93],"within":[96],"model\u2019s":[99],"textual":[100],"embedding":[101],"space.":[102],"This":[103],"universal":[104],"(P\u2217)":[107],"directly":[108],"moderates":[109],"NSFW":[110,159],"inputs,":[111],"enabling":[112],"safe":[113],"yet":[114],"realistic":[115],"image":[116],"generation":[117,161],"without":[118],"altering":[119],"inference":[121],"efficiency":[122],"or":[123],"requiring":[124],"proxy":[125],"models.We":[126],"further":[127],"enhance":[128],"its":[129,191],"reliability":[130],"helpfulness":[132],"through":[133],"divide-and-conquer":[135],"strategy,":[136],"which":[137],"optimizes":[138],"category-specific":[139],"prompts":[141],"combines":[143],"them":[144],"into":[145],"holistic":[146],"guidance.":[148],"Extensive":[149],"experiments":[150],"across":[151],"five":[152],"datasets":[153],"demonstrate":[154],"PromptGuard":[156,167],"effectively":[157],"mitigates":[158],"while":[162],"preserving":[163],"benign":[165],"outputs.":[166],"achieves":[168],"3.8":[169],"times":[170],"faster":[171],"than":[172],"prior":[173],"methods,":[176],"surpassing":[177],"eight":[178],"state-of-the-art":[179],"defenses.":[180],"Rigorous":[181],"evaluation":[182],"using":[183],"both":[184],"multi-head":[185],"classifiers":[186],"VLM-based":[188],"guardrails":[189],"confirms":[190],"robustness,":[192],"achieving":[193],"optimal":[195],"average":[196],"unsafe":[197],"ratios":[198],"down":[199],"5.84%":[201],"6.18%,":[203],"respectively.":[204],"code":[206],"dataset":[208],"available":[210],"at":[211],"https://t2ipromptguard.":[212],"github.io/.":[213]},"counts_by_year":[],"updated_date":"2026-08-21T09:56:20.448147","created_date":"2026-02-22T00:00:00"}
