[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"doc-detail-83766-en":3,"doc-seo-83766-105":30,"detail-sidebar-cat-0-en-105":91},{"code":4,"msg":5,"data":6},0,"success",{"doc_id":7,"user_id":8,"nickname":9,"user_avatar":10,"doc_module":4,"category_id":11,"category_name":12,"doc_title":13,"doc_description":14,"doc_content":15,"file_id":16,"file_url":17,"file_type":18,"file_size":19,"view_count":20,"is_deleted":4,"is_public":21,"is_downloadable":21,"audit_status":21,"page_count":22,"language":23,"language_code":24,"site_id":25,"html_lang":24,"table_of_contents":26,"faqs":27,"seo_title":13,"seo_description":14,"update_tm":28,"read_time":29},83766,137441390410,"Hazel","https://ap-avatar.wpscdn.com/avatar/2000252f4ab5702993?_k=1776741390130283984",8,"Research & Report","Data Structures for Private Token Transfers in TEE-Based Networks","Trusted execution environment (TEE) based confidential smart contract networks improve privacy for sensitive contract data, yet token transfers remain exposed to storage access pattern attacks. When contracts update recipient balances using encrypted key-value stores, the unique (recipient-linked) keys accessed during execution can reveal sender–recipient relationships. This paper proposes two domain-specific data structures—Delayed Write Buffer (DWB) and Bitwise-Trie of Bucketed Entries (BTBE)—to break direct correlations while limiting overhead, plus a private notification mechanism for real-time privacy-preserving push updates.","arXiv :2607 .04032v 1 [ cs .CR] 4 Jul 2026  \nData Structures for Private Token Transfers in TEE-Based Networks  \nBlake Regalia 1 and Benjamin Adams2[0000−0002−1657−9809]  \n1 Solar Republic LLC, USA, [blake.regalia@gmail.com](blake.regalia@gmail.com)  \n2 Department of Computer Science and Software Engineering, University of  \nCanterbury, New Zealand, [benjamin.adams@canterbury.ac.nz](benjamin.adams@canterbury.ac.nz)  \nAbstract. Trusted execution environment (TEE) based confidential smart contract networks promise privacy but remain vulnerable to storage access pattern attacks that can link senders and recipients in token transfers. When contracts update recipient balances during transfers, the unique storage keys accessed reveal transaction relationships even when data is encrypted. This paper introduces two novel data structures to address this vulnerability: the Delayed Write Buffer (DWB) and the Bitwise-Trie of Bucketed Entries (BTBE) . The DWB delays recipient balance updates by buffering pending transfers and randomly settling entries, breaking the direct correlation between transfer execution and recipient storage access. The BTBE further enhances privacy by grouping addresses into constant-sized buckets, preventing flooding attacks and creating anonymity sets for balance queries. Additionally, we present a private notification system enabling real-time, privacy-preserving push notifications for confidential contracts. Our domain-specific approach leverages the unique characteristics of token transfers—asymmetric balance updates and tolerance for delayed settlement—to achieve practical performance with probabilistic anonymity guarantees.  \nKeywords: Private transfer · Smart contract · Trusted execution environment.  \n1 Introduction  \nTrusted execution environment (TEE) based confidential smart contract networks have emerged in recent years in recognition of the limitations posed by public blockchain databases [18, 21] . These networks leverage hardware-based isolation to execute smart contract code securely, with the intention that sensitive data remains confidential from external observers and even from the network node operators. Programmable privacy provides application-level privacy, which provides a flexible set of privacy characteristics for users beyond simple transactional privacy [2] . Examples of blockchains that now implement programmable privacy with TEEs include Secret Network, Oasis, and Phala [8, 24, 25] . Beyond these, TEE-based confidential features are increasingly being adopted by other natively public chains. TEE network confidentiality is touted as enabling a number of new types of privacy-preserving financial applications, given that TEEs are  \n2 B. Regalia and B. Adams  \nfar more efficient than competing privacy technologies such as zero-knowledge proof systems (for two-party interaction) or fully homomorphic encryption.  \nFor Secret Network and Oasis, data confidentiality is implemented in the database record through encrypted keys and values. This approach leaves applications such as token contracts susceptible to access-pattern attacks when they are implemented naively, e.g. via a simple translation of the ERC20 standard [10, 15] . When performing token transfers, secret contracts must store balancesand transfer histories in their internal (encrypted) key-value databases. However, even though the database key is encrypted, it is unique to the recipient. This allows an attacker to monitor which database keys are read from and written to each execution to deduce storage access patterns and thus correlate transfers toa particular recipient the next time that key is read from or written to. Since the contract must access a sender’s balance when executing an outgoing transfer (to make sure they have enough to cover the spend), this leads to a conundrum: how can we update a recipient’s balance during a transfer without accessing a storage area associated with their account?  \nJean et al. [15] demonstra","cbCaik4WNFLRTwqy","https://ap.wps.com/l/cbCaik4WNFLRTwqy","pdf",1254698,3,1,21,"English","en",105,"# Introduction\n## TEE-based confidential smart contract networks\n## Storage access pattern attacks in token transfers\n## Related work and limitations (decoys and ORAM)\n## Proposed approach (DWB, BTBE) and private notifications","[{\"question\":\"Why do storage access pattern attacks still work in TEE-based confidential token transfers?\",\"answer\":\"Because recipient balances and transfer histories are stored in the contract’s encrypted key-value database with recipient-unique keys. Even with encryption, the set of keys read and written during execution can be observed to infer storage access patterns and correlate transfers.\"},{\"question\":\"What is the Delayed Write Buffer (DWB) and what problem does it solve?\",\"answer\":\"DWB delays recipient balance updates by buffering pending transfers and settling entries later in randomized form. This breaks the direct correlation between transfer execution and the recipient storage accesses that would otherwise reveal relationships.\"},{\"question\":\"How does the Bitwise-Trie of Bucketed Entries (BTBE) improve privacy?\",\"answer\":\"BTBE groups addresses into constant-sized buckets, preventing flooding attacks and creating anonymity sets for balance queries. This helps make recipient identification less precise than direct per-address access.\"}]",1784190291,53,{"code":4,"msg":31,"data":32},"ok",{"site_id":25,"language":24,"slug":33,"title":13,"keywords":34,"description":14,"schema_data":35,"social_meta":86,"head_meta":88,"extra_data":90,"updated_unix":28},"data-structures-for-private-token-transfers-in-tee-based-networks","",{"@graph":36,"@context":85},[37,53,68],{"@type":38,"itemListElement":39},"BreadcrumbList",[40,44,48,50],{"item":41,"name":42,"@type":43,"position":21},"https://docshare.wps.com","Home","ListItem",{"item":45,"name":46,"@type":43,"position":47},"https://docshare.wps.com/document/","Document",2,{"item":49,"name":12,"@type":43,"position":20},"https://docshare.wps.com/document/research-report/",{"item":51,"name":13,"@type":43,"position":52},"https://docshare.wps.com/document/data-structures-for-private-token-transfers-in-tee-based-networks/83766/",4,{"url":51,"name":13,"@type":54,"author":55,"headline":13,"publisher":57,"fileFormat":60,"inLanguage":24,"description":14,"dateModified":61,"datePublished":62,"encodingFormat":60,"isAccessibleForFree":63,"interactionStatistic":64},"DigitalDocument",{"name":9,"@type":56},"Person",{"url":41,"name":58,"@type":59},"DocShare","Organization","application/pdf","2026-07-25","2026-07-16",true,{"@type":65,"interactionType":66,"userInteractionCount":20},"InteractionCounter",{"@type":67},"ViewAction",{"@type":69,"mainEntity":70},"FAQPage",[71,77,81],{"name":72,"@type":73,"acceptedAnswer":74},"Why do storage access pattern attacks still work in TEE-based confidential token transfers?","Question",{"text":75,"@type":76},"Because recipient balances and transfer histories are stored in the contract’s encrypted key-value database with recipient-unique keys. Even with encryption, the set of keys read and written during execution can be observed to infer storage access patterns and correlate transfers.","Answer",{"name":78,"@type":73,"acceptedAnswer":79},"What is the Delayed Write Buffer (DWB) and what problem does it solve?",{"text":80,"@type":76},"DWB delays recipient balance updates by buffering pending transfers and settling entries later in randomized form. This breaks the direct correlation between transfer execution and the recipient storage accesses that would otherwise reveal relationships.",{"name":82,"@type":73,"acceptedAnswer":83},"How does the Bitwise-Trie of Bucketed Entries (BTBE) improve privacy?",{"text":84,"@type":76},"BTBE groups addresses into constant-sized buckets, preventing flooding attacks and creating anonymity sets for balance queries. 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