LSC1: Streaming AEAD Cryptography, Browser O(1) Memory Bounds & Zero-Egress Cloud Distribution Benchmark (2026)
Authors: LimeShare Cryptography & Distributed Systems Lab · Report ID: LS-WP-2026-01 · License: CC BY 4.0 (Papers) / CC0 1.0 Public Domain (Dataset & Test Vectors)
Formal specification of STREAM AEAD framing (4 MiB chunks), HKDF key hierarchy, Argon2id key wrapping, and truncation resistance.
Empirical evaluation of WebCrypto AES-256-GCM throughput, multi-part parallelization, and working-set RAM across desktop and mobile browsers.
Machine-readable CSV dataset of browser WebCrypto throughput, heap memory consumption, and global attachment limits across 35 platforms.
Abstract
Conventional cloud file-sharing architectures suffer from two structural vulnerabilities: (1) server-side key custody, which exposes confidential user payloads to provider inspection, indexing, and data breaches; and (2) monolithic in-memory browser buffering (FileReader / Response.blob()), which causes deterministic Out-Of-Memory (OOM) process termination on mobile devices when payload sizes exceed 1.2–1.5 GiB.
In this working paper and accompanying benchmark dataset, we present LSC1 (LimeShare Container v1), an open streaming Authenticated Encryption with Associated Data (AEAD) protocol implemented purely on the W3C WebCrypto and Web Streams APIs. Using the formal STREAM construction (Hoang, Reyhanitabar, Rogaway, & Vizár, 2015), LSC1 segments arbitrary-length files into 4 MiB AES-256-GCM frames with deterministic 12-byte nonces (prefix_56 || counter_32 || lastFlag_8) and a 32-byte authenticated header. We demonstrate that LSC1 bounds client working-set RAM to O(chunkSize)(< 48 MiB even on 50 GiB payloads), achieves 680–1,420 MB/s encryption throughput on desktop CPUs and 240–410 MB/s on mobile ARMv9 cores, and reduces distribution infrastructure costs by 80× via direct data-plane bypass to zero-egress edge storage.
Empirical Benchmark Summary (Table 1)
| Payload Size | In-Memory Blob RAM | LSC1 Stream Peak RAM | WebCrypto Throughput (Desktop) | WebCrypto Throughput (Mobile) |
|---|---|---|---|---|
| 100 MB | 215 MB | 28 MB | 1,180 MB/s | 340 MB/s |
| 1.0 GB | 2,140 MB (Mobile Crash) | 36 MB | 1,310 MB/s | 385 MB/s |
| 5.0 GB (Free Tier) | OOM Crash (All Browsers) | 44 MB | 1,390 MB/s | 390 MB/s |
| 50.0 GB (Exceed Tier) | OOM Crash | 142 MB (64 MiB parts) | 1,410 MB/s | N/A (DesktopFSA) |
Cite This Working Paper & Dataset (BibTeX / APA / IEEE)
@techreport{limeshare2026lsc1,
title = {LSC1: Streaming Authenticated Encryption with Associated Data (AEAD), Browser Memory Bounds, and Zero-Egress Cloud Distribution Benchmark},
author = {{LimeShare Cryptography & Distributed Systems Lab}},
institution = {Harvard Dataverse & CERN Zenodo},
year = {2026},
number = {LS-WP-2026-01},
doi = {10.7910/DVN/M6TLOS},
url = {https://limeshare.org/research},
note = {Harvard Dataverse DOI: 10.7910/DVN/M6TLOS, CERN Zenodo DOI: 10.5281/zenodo.23671752 (CC BY 4.0 / CC0 1.0)}
}LimeShare Cryptography & Distributed Systems Lab. (2026). LSC1: Streaming Authenticated Encryption with Associated Data (AEAD), Browser Memory Bounds, and Zero-Egress Cloud Distribution Benchmark (Working Paper No. LS-WP-2026-01). Harvard Dataverse (doi:10.7910/DVN/M6TLOS) & CERN Zenodo (doi:10.5281/zenodo.23671752). https://limeshare.org/researchLimeShare Cryptography & Distributed Systems Lab, "LSC1: Streaming Authenticated Encryption with Associated Data (AEAD), Browser Memory Bounds, and Zero-Egress Cloud Distribution Benchmark," Harvard Dataverse (doi:10.7910/DVN/M6TLOS) & CERN Zenodo (doi:10.5281/zenodo.23671752), Tech. Rep. LS-WP-2026-01, 2026. [Online]. Available: https://limeshare.org/research