kem

Traits for Key Encapsulation Mechanisms (KEMs): public-key cryptosystems designed to enable a sender (a.k.a. encapsulator) to generate and encrypt a short secret key and transmit it to a receiver (a.k.a. decapsulator) confidentially

0.3.0 5.2M downloads/mo #4460 most downloaded on crates.io RustCrypto/traits

What this package is like to depend on

Last release 4 months ago

03 Apr 2026

Ships unpredictably

gaps range from 1 weeks to 1.9 years

Nearly every release is documented

notes for 3 of 3 stable releases

12 versions withdrawn

withdrawn after publishing

6 years old

23 releases · first in 2021

19 releases in the last 12 months

see the full history below

Release timeline

23 releases · Feb 2021 to Apr 2026

2022 2023 2024 2025 2026

Release Pre-release Withdrawn

Releases

latest 23

0.4.0-rc.5 23 Jan 2026 pre-release withdrawn

Nothing published for this version
0.4.0-rc.4 20 Jan 2026 pre-release withdrawn

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0.4.0-rc.3 19 Jan 2026 pre-release withdrawn

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0.4.0-rc.2 09 Jan 2026 pre-release withdrawn

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0.4.0-rc.1 27 Dec 2025 pre-release withdrawn

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0.4.0-rc.0 26 Dec 2025 pre-release withdrawn

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0.4.0-pre.2 05 Nov 2025 pre-release withdrawn

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0.4.0-pre.1 31 Oct 2025 pre-release withdrawn

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0.4.0-pre.0 30 Oct 2025 pre-release withdrawn

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0.3.0 03 Apr 2026
Release notes
This release is effectively a complete rewrite of the kem crate. Any similarities between trait names in this release and previous releases is coincidental. The log below highlights some of the new parts of the API but will provide an incomplete picture of changes.

Added
- Encapsulate and Decapsulate traits (#1509)
- getrandom feature (#2140)
- Re-exports from crypto-common (#2222)
  - re-exports crypto-common itself as common
  - re-exports KeyInit, which is useful for seeds
  - re-exports Key as the type for representing serialized encapsulation and decapsulation keys
  - re-exports InvalidKey as the error when TryKeyInit fails
- TryDecapsulate trait (#2220, #2235)
- Kem trait for the whole algorithm type family (#2243)
- FromSeed trait and Seed type alias (#2284)
Changed
- Decapsulator trait replaced with new implementation ([#2282])
Removed
- Previous implementation (#1509)
Changed
- Edition changed to 2024 and MSRV bumped to 1.85 (#1759)
- Bump rand_core to v0.10 (#2250)
Open source →
0.3.0-rc.6 05 Feb 2026 pre-release

Nothing published for this version
0.3.0-rc.5 05 Feb 2026 pre-release

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0.3.0-rc.4 01 Feb 2026 pre-release

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0.3.0-rc.3 30 Jan 2026 pre-release

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0.3.0-rc.2 24 Jan 2026 pre-release

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0.3.0-rc.1 24 Jan 2026 pre-release

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0.3.0-rc.0 23 Jan 2026 pre-release

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0.3.0-pre.2 27 Oct 2025 pre-release withdrawn

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0.3.0-pre.1 25 Oct 2025 pre-release withdrawn

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0.3.0-pre.0 17 Apr 2024 pre-release

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0.2.0 26 May 2022
Release notes
Added
- Generic SharedSecret type (#982)
- EncappedKey::EncappedKeySize associated constant (#982)
Changed
- Rename EncappedKey::NSecret => EncappedKey::SharedSecretSize (#982)
- Add EncappedKey::{from_bytes, as_bytes} methods (#982)
Open source →
0.1.0 03 Jan 2022
Release notes
- Initial release
Open source →
0.0.0 09 Feb 2021 withdrawn

Nothing published for this version

kem

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