Data stored in glass could last over 10,000 years, Microsoft says

Enterprises struggling with the cost and complexity of long-term data archival could soon have a new option: a piece of glass.

New research published on Wednesday suggests that a borosilicate glass plate 120mm square and just 2mm thick can store 4.8TB of data across 301 layers with accelerated aging tests, indicating that the data would remain intact for at least 10,000 years.

“Glass is a permanent data storage material that is resistant to water, heat, and dust,” Microsoft researchers wrote in a paper published in the science and technology journal, Nature. “We have unlocked the science for parallel high-speed writing and developed a technique to permit accelerated aging tests on the written glass, suggesting that the data should remain intact for at least 10,000 years.”

Previous versions of the technology required fused silica, a high-purity glass available from only a handful of manufacturers. The new findings show the system works equally well with borosilicate — widely manufactured and significantly cheaper — bringing the technology a step closer to commercial viability, the paper added.

The timing is significant.

The global datasphere is doubling approximately every three years, according to Seagate research cited in the paper, yet “most digital archive systems rely on media that degrade” well short of the multi-decade retention timescales that legal, financial, and regulatory obligations increasingly demand, the authors noted.

Magnetic tape, the most widely deployed archival medium today, reflects those constraints. An LTO-10 (Linear Tape-Open) cartridge, the current enterprise benchmark, holds 30TB to 40TB native at 400MB/s, but its rated shelf life is just 30 years. It requires climate-controlled storage between 16°C and 25°C and migration roughly every five to ten years.

That operational overhead, analysts say, is the real cost of tape — not the media. “Archival estates rarely fail because cartridges chemically degrade on schedule,” said Sanchit Vir Gogia, chief analyst at Greyhound Research. “They fail because compatibility windows close, drive generations evolve, firmware support sunsets, and robotics require refresh.”

Tape-as-a-service models have shifted some of that burden, noted Vishesh Divya, principal analyst at Gartner, moving hardware lifecycle management to providers under defined service-level assurances.

“LTO tape remains the benchmark for enterprise cold storage,” he said. “The media cost per terabyte remains low, the ecosystem is mature, and enterprises have decades of operational experience managing refresh cycles,” Divya said.

Sony’s Optical Disc Archive — the main optical alternative at 5.5TB per cartridge with a 100-year rated shelf life — was discontinued in March 2025, leaving no comparable product on the market.

How data is written and read from the glass

Project Silica, Microsoft’s glass-based storage initiative, uses femtosecond laser pulses to encode data as three-dimensional structures called voxels inside the glass, at 25.6 megabits per second per beam and an energy cost of 10.1 nanojoules per bit.

The paper describes two encoding methods. The first method, birefringent voxels, modifies the polarization properties of the glass. The team reduced the laser pulses required to a pseudo-single-pulse technique — one pulse split to simultaneously begin one voxel and complete another — enabling faster beam scanning.

The second method, phase voxels, is a new invention that modifies the phase properties of the glass instead and requires only a single pulse per voxel. Crucially, it works in borosilicate glass, where the birefringent approach did not. “Much higher levels of three-dimensional inter-symbol interference in phase voxels can be mitigated with a machine learning classification model,” the researchers wrote.

Earlier Project Silica readers required three or four cameras to retrieve data; the updated system requires one, completing what the researchers described as the first fully demonstrated end-to-end glass archival system, from writing and storage through to retrieval.

Longevity verified through accelerated aging

The longevity claim is backed by a nondestructive optical method the team developed to measure voxel degradation in place, combined with accelerated aging techniques applied to written borosilicate samples. “Accelerated ageing tests on written voxels in borosilicate suggest data lifetimes exceeding 10,000 years,” the researchers noted.

For enterprise buyers, longevity alone will not make the case.

“A realistic TCO comparison must be modelled across multi-decade lifecycle horizons, not procurement cycles,” said Gogia. “Glass storage reframes the economic curve by potentially eliminating migration cycles — reducing labour, reconciliation overhead, and operational disruption.” Write speeds remain materially slower than tape, however, making glass better suited to ultra-cold, low-ingestion estates.

Compliance adds a further dimension. Data encoded as permanent optical modifications cannot be overwritten, reducing ransomware exposure. But “compliance is a system property, not a substrate property,” Gogia cautioned. “Enterprises must still ensure encryption key rotation, metadata indexing, and audit trail completeness. A 10,000-year medium does not remove the obligation to demonstrate governance discipline.”

No commercial product yet

Microsoft said in a separate blog post that the research phase of Project Silica is now complete. “We are continuing to consider learnings from Project Silica as we explore the ongoing need for sustainable, long-term preservation of digital information,” the company said, without disclosing a commercialization roadmap. If commercialized, glass storage is unlikely to displace tape.

“It is more likely to emerge as a specialized ultra-long retention rather than a replacement for tape-based cold storage,” said Gartner’s Divya. “Any new medium would have to compete on the full-stack equation — economics, hardware, software, and operational model — not just on media longevity.”Data stored in glass could last over 10,000 years, Microsoft says – ComputerworldRead More