remove extra files, continue rename process

The previously existing polynomial coefficients had an inverse bias
towards `0`, only starting higher than `1`. This allows `0` to be a
valid polynomial.

As per an audit performed by Cure53:

> The correct method to select a random polynomial would be to select
all coefficients (including the most significant coefficient) uniformly
in the range 0..255 (inclusive). Otherwise, knowledge that a coefficient
in a polynomial cannot be 0 permits the exclusion of single byte values
for the shared secret given one share less than required. [...]
Exploiting this weakness necessitates sharing the same secret multiple
times. In this scenario, an attacker could exclude an exponential number
of values for each of the shared bytes until sufficiently few values
remain for brute forcing.  Cure53 estimates that under ideal
circumstances (e.g., a 2-out-of-N scheme) a shared secret can be
reconstructed if the same secret has been distributed 500-1500 times.

.github/workflows/rust.yml

@@ -18,7 +18,7 @@ jobs:
           command: check
 
   test-std:
-    name: Test
+    name: Test std
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2
@@ -32,7 +32,7 @@ jobs:
           command: test
 
   test-nostd:
-    name: Test
+    name: Test no-std
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2

CHANGELOG.md

@@ -4,6 +4,35 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [0.6.0] - 2024-11-16
+### Changed
+- Rename project to `blahaj` following soft-fork
+- Use `u8::MAX` instead of deprecated `u8::max_value()`
+- Upgraded project dependencies
+
+### Fixed
+- Lower bound of polynomial coefficients changed from 1 to 0
+
+## [0.5.0] - 2021-03-14
+### Added
+- Zeroize memory on drop for generated secret shares
+
+## [0.4.3] - 2021-02-04
+### Changed
+- Upgraded project dependencies
+
+## [0.4.2] - 2020-08-03
+### Fixed
+- Small fix in docs
+
+## [0.4.1] - 2020-04-23
+### Added
+- Fuzz tests
+
+### Fixed
+- Unexpected panic when trying to recover secret from different length shares
+- Unexpected panic when trying to convert less than 2 bytes to `Share`
+
 ## [0.4.0] - 2020-04-02
 ### Added
 - It is now possible to compile without `std` with `--no-default-features`

COPYRIGHT

@@ -1,12 +1,11 @@
-Copyrights in the Sharks project are retained by their contributors. No
+Copyrights in the Blahaj project are retained by their contributors. No
-copyright assignment is required to contribute to the Sharks project.
+copyright assignment is required to contribute to the Blahaj project.
 
 For full authorship information, see the version control history.
 
 Except as otherwise noted (below and/or in individual files), Sharks is
-licensed under the Apache License, Version 2.0 <LICENSE-APACHE> or
+licensed under the MIT license <LICENSE-MIT> or
-<http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+<http://opensource.org/licenses/MIT>.
-<LICENSE-MIT> or <http://opensource.org/licenses/MIT>, at your option.
 
-The Sharks project includes code from the Rust project
+The Blahaj project includes code from the Rust project published under these
-published under these same licenses.
+same licenses.

Cargo.toml

@@ -1,32 +1,31 @@
 [package]
-name = "sharks"
+name = "blahaj"
-version = "0.4.0"
+version = "0.6.0"
-authors = ["Aitor Ruano <codearm@pm.me>"]
+authors = ["Ryan Heywood <ryan@distrust.co>"]
-description = "Fast, small and secure Shamir's Secret Sharing library crate"
+description = "Fast, small, and secure Shamir's Secret Sharing"
-homepage = "https://github.com/c0dearm/sharks"
+homepage = "https://git.distrust.co/public/blahaj"
-repository = "https://github.com/c0dearm/sharks"
+repository = "https://git.distrust.co/public/blahaj"
 readme = "README.md"
-keywords = ["shamir", "secret", "sharing", "share", "crypto"]
+keywords = ["shamir", "secret", "sharing", "share", "cryptography"]
 categories = ["algorithms", "cryptography", "mathematics"]
-license = "MIT/Apache-2.0"
+license = "MIT"
-edition = "2018"
+edition = "2021"
 
-[badges]
-maintenance = { status = "actively-developed" }
-codecov = { repository = "c0dearm/sharks" }
-
-# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 [features]
-default = ["std"]
+default = ["std", "zeroize_memory"]
-std = ["rand/std"]
+std = ["rand/std", "rand/std_rng"]
+fuzzing = ["std", "arbitrary"]
+zeroize_memory = ["zeroize"]
 
 [dependencies]
-rand = { version = "0.7", default-features = false }
+rand = { version = "0.8", default-features = false }
-hashbrown = "0.7"
+hashbrown = "0.15"
+arbitrary = { version = "0.4.7", features = ["derive"], optional = true }
+zeroize = { version = "1.2.0", features = ["zeroize_derive"], optional = true }
 
 [dev-dependencies]
 criterion = "0.3"
-rand_chacha = "0.2"
+rand_chacha = "0.3"
 
 [[bench]]
 name = "benchmarks"

LICENSE-APACHE

@@ -1,201 +0,0 @@
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-
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-      of your accepting any such warranty or additional liability.
-
-   END OF TERMS AND CONDITIONS
-
-   APPENDIX: How to apply the Apache License to your work.
-
-      To apply the Apache License to your work, attach the following
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README.md

@@ -1,15 +1,12 @@
-# Sharks
+# Blahaj
 
-[![Rust](https://github.com/c0dearm/sharks/workflows/Rust/badge.svg?branch=master)](https://github.com/c0dearm/sharks/actions)
+[![Crates](https://img.shields.io/crates/v/blahaj.svg)](https://crates.io/crates/blahaj)
-[![Crates](https://img.shields.io/crates/v/sharks.svg)](https://crates.io/crates/sharks)
+[![Docs](https://docs.rs/blahaj/badge.svg)](https://docs.rs/blahaj)
-[![Docs](https://docs.rs/sharks/badge.svg)](https://docs.rs/sharks)
-[![Codecov](https://codecov.io/gh/c0dearm/sharks/branch/master/graph/badge.svg)](https://codecov.io/gh/c0dearm/sharks)
-[![License](https://camo.githubusercontent.com/47069b7e06b64b608c692a8a7f40bc6915cf629c/68747470733a2f2f696d672e736869656c64732e696f2f62616467652f6c6963656e73652d417061636865322e302532464d49542d626c75652e737667)](https://github.com/c0dearm/sharks/blob/master/COPYRIGHT)
 
 Fast, small and secure [Shamir's Secret Sharing](https://en.wikipedia.org/wiki/Shamir%27s_Secret_Sharing) library crate
 
 Documentation:
--    [API reference (docs.rs)](https://docs.rs/sharks)
+-    [API reference (docs.rs)](https://docs.rs/blahaj)
 
 ## Usage
 
@@ -17,17 +14,17 @@ Add this to your `Cargo.toml`:
 
 ```toml
 [dependencies]
-sharks = "0.4"
+blahaj = "0.6"
 ```
 
 If your environment doesn't support `std`:
 
 ```toml
 [dependencies]
-sharks = { version = "0.4", default-features = false }
+blahaj = { version = "0.6", default-features = false }
 ```
 
-To get started using Sharks, see the [Rust docs](https://docs.rs/sharks)
+To get started using Blahaj, see the [Rust docs](https://docs.rs/blahaj)
 
 ## Features
 
@@ -58,19 +55,15 @@ You can run them with `cargo test` and `cargo bench`.
 | ----------------------------------------- | ------------------------------- | ------------------------------- | ------------------------------- | ------------------------------- | ------------------------------- |
 | Intel(R) Core(TM) i7-8550U CPU @ 1.80GHz  | [1.4321 us 1.4339 us 1.4357 us] | [1.3385 ns 1.3456 ns 1.3552 ns] | [228.77 us 232.17 us 236.23 us] | [24.688 ns 25.083 ns 25.551 ns] | [22.832 ns 22.910 ns 22.995 ns] |
 | Intel(R) Core(TM) i7-8565U CPU @ 1.80GHz  | [1.3439 us 1.3499 us 1.3562 us] | [1.5416 ns 1.5446 ns 1.5481 ns] | [197.46 us 198.37 us 199.22 us] | [20.455 ns 20.486 ns 20.518 ns] | [18.726 ns 18.850 ns 18.993 ns] |
+| Apple M1 ARM (Macbook Air)                | [3.3367 us 3.3629 us 3.4058 us] | [741.75 ps 742.65 ps 743.52 ps] | [210.14 us 210.23 us 210.34 us] | [27.567 ns 27.602 ns 27.650 ns] | [26.716 ns 26.735 ns 26.755 ns] |
 
 # Contributing
 
-If you find a vulnerability, bug or would like a new feature, [open a new issue](https://github.com/c0dearm/sharks/issues/new).
+If you find a vulnerability, bug or would like a new feature, reach out to
-
+<mailto:team@distrust.co>.
-To introduce your changes into the codebase, submit a Pull Request.
-
-Many thanks!
 
 # License
 
-Sharks is distributed under the terms of both the MIT license and the
+Blahaj is distributed under the terms of the MIT license.
-Apache License (Version 2.0).
 
-See [LICENSE-APACHE](LICENSE-APACHE) and [LICENSE-MIT](LICENSE-MIT), and
+See [LICENSE-MIT](LICENSE-MIT) and [COPYRIGHT](COPYRIGHT) for details.
-[COPYRIGHT](COPYRIGHT) for details.

benches/benchmarks.rs

@@ -1,6 +1,7 @@
 use criterion::{black_box, criterion_group, criterion_main, Criterion};
+use std::convert::TryFrom;
 
-use sharks::{Share, Sharks};
+use blahaj::{Share, Sharks};
 
 fn dealer(c: &mut Criterion) {
     let sharks = Sharks(255);
@@ -24,10 +25,10 @@ fn recover(c: &mut Criterion) {
 fn share(c: &mut Criterion) {
     let bytes_vec = vec![1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
     let bytes = bytes_vec.as_slice();
-    let share = Share::from(bytes);
+    let share = Share::try_from(bytes).unwrap();
 
     c.bench_function("share_from_bytes", |b| {
-        b.iter(|| Share::from(black_box(bytes)))
+        b.iter(|| Share::try_from(black_box(bytes)))
     });
 
     c.bench_function("share_to_bytes", |b| {

codecov.yml

@@ -1,20 +0,0 @@
-codecov:
-  require_ci_to_pass: yes
-
-coverage:
-  precision: 2
-  round: down
-  range: "90...100"
-
-parsers:
-  gcov:
-    branch_detection:
-      conditional: yes
-      loop: yes
-      method: no
-      macro: no
-
-comment:
-  layout: "reach,diff,flags,tree"
-  behavior: default
-  require_changes: no

fuzz/.gitignore

@@ -0,0 +1,4 @@
+
+target
+corpus
+artifacts

fuzz/Cargo.toml

@@ -0,0 +1,38 @@
+
+[package]
+name = "sharks-fuzz"
+version = "0.0.0"
+authors = ["Automatically generated"]
+publish = false
+edition = "2018"
+
+[package.metadata]
+cargo-fuzz = true
+
+[dependencies]
+libfuzzer-sys = "0.3"
+arbitrary = { version = "0.4.2", features = ["derive"] }
+
+[dependencies.sharks]
+path = ".."
+features = ["fuzzing"]
+
+# Prevent this from interfering with workspaces
+[workspace]
+members = ["."]
+
+[[bin]]
+name = "deserialize_share"
+path = "fuzz_targets/deserialize_share.rs"
+
+[[bin]]
+name = "serialize_share"
+path = "fuzz_targets/serialize_share.rs"
+
+[[bin]]
+name = "generate_shares"
+path = "fuzz_targets/generate_shares.rs"
+
+[[bin]]
+name = "recover"
+path = "fuzz_targets/recover.rs"

fuzz/fuzz_targets/deserialize_share.rs

@@ -0,0 +1,8 @@
+#![no_main]
+use core::convert::TryFrom;
+use libfuzzer_sys::fuzz_target;
+use sharks::Share;
+
+fuzz_target!(|data: &[u8]| {
+    let _share = Share::try_from(data);
+});

fuzz/fuzz_targets/generate_shares.rs

@@ -0,0 +1,19 @@
+#![no_main]
+use libfuzzer_sys::fuzz_target;
+
+use arbitrary::Arbitrary;
+use sharks::{Share, Sharks};
+
+#[derive(Debug, Arbitrary)]
+struct Parameters {
+    pub threshold: u8,
+    pub secret: Vec<u8>,
+    pub n_shares: usize,
+}
+
+fuzz_target!(|params: Parameters| {
+    let sharks = Sharks(params.threshold);
+    let dealer = sharks.dealer(&params.secret);
+
+    let _shares: Vec<Share> = dealer.take(params.n_shares).collect();
+});

fuzz/fuzz_targets/recover.rs

@@ -0,0 +1,16 @@
+#![no_main]
+use libfuzzer_sys::fuzz_target;
+
+use arbitrary::Arbitrary;
+use sharks::{Share, Sharks};
+
+#[derive(Debug, Arbitrary)]
+struct Parameters {
+    pub threshold: u8,
+    pub shares: Vec<Share>,
+}
+
+fuzz_target!(|params: Parameters| {
+    let sharks = Sharks(params.threshold);
+    let _secret = sharks.recover(&params.shares);
+});

fuzz/fuzz_targets/serialize_share.rs

@@ -0,0 +1,8 @@
+#![no_main]
+use libfuzzer_sys::fuzz_target;
+
+use sharks::Share;
+
+fuzz_target!(|share: Share| {
+    let _data: Vec<u8> = (&share).into();
+});

src/field.rs

@@ -4,6 +4,12 @@
 use core::iter::{Product, Sum};
 use core::ops::{Add, Div, Mul, Sub};
 
+#[cfg(feature = "fuzzing")]
+use arbitrary::Arbitrary;
+
+#[cfg(feature = "zeroize_memory")]
+use zeroize::Zeroize;
+
 const LOG_TABLE: [u8; 256] = [
     0x00, 0x00, 0x01, 0x19, 0x02, 0x32, 0x1a, 0xc6, 0x03, 0xdf, 0x33, 0xee, 0x1b, 0x68, 0xc7, 0x4b,
     0x04, 0x64, 0xe0, 0x0e, 0x34, 0x8d, 0xef, 0x81, 0x1c, 0xc1, 0x69, 0xf8, 0xc8, 0x08, 0x4c, 0x71,
@@ -58,7 +64,10 @@ const EXP_TABLE: [u8; 512] = [
     0x58, 0xb0, 0x7d, 0xfa, 0xe9, 0xcf, 0x83, 0x1b, 0x36, 0x6c, 0xd8, 0xad, 0x47, 0x8e, 0x01, 0x02,
 ];
 
-#[derive(Debug, PartialEq, Copy, Clone)]
+#[derive(Debug, PartialEq, Clone)]
+#[cfg_attr(feature = "fuzzing", derive(Arbitrary))]
+#[cfg_attr(feature = "zeroize_memory", derive(Zeroize))]
+#[cfg_attr(feature = "zeroize_memory", zeroize(drop))]
 pub struct GF256(pub u8);
 
 #[allow(clippy::suspicious_arithmetic_impl)]

src/lib.rs

@@ -2,7 +2,7 @@
 //!
 //! Usage example (std):
 //! ```
-//! use sharks::{ Sharks, Share };
+//! use blahaj::{ Sharks, Share };
 //!
 //! // Set a minimum threshold of 10 shares
 //! let sharks = Sharks(10);
@@ -20,7 +20,7 @@
 //!
 //! Usage example (no std):
 //! ```
-//! use sharks::{ Sharks, Share };
+//! use blahaj::{ Sharks, Share };
 //! use rand_chacha::rand_core::SeedableRng;
 //!
 //! // Set a minimum threshold of 10 shares
@@ -34,7 +34,7 @@
 //! let secret = sharks.recover(shares.as_slice()).unwrap();
 //! assert_eq!(secret, vec![1, 2, 3, 4]);
 //! ```
-#![no_std]
+#![cfg_attr(not(feature = "std"), no_std)]
 
 mod field;
 mod math;
@@ -53,7 +53,7 @@ pub use share::Share;
 ///
 /// Usage example:
 /// ```
-/// # use sharks::{ Sharks, Share };
+/// # use blahaj::{ Sharks, Share };
 /// // Set a minimum threshold of 10 shares
 /// let sharks = Sharks(10);
 /// // Obtain an iterator over the shares for secret [1, 2, 3, 4]
@@ -79,7 +79,7 @@ impl Sharks {
     ///
     /// Example:
     /// ```
-    /// # use sharks::{ Sharks, Share };
+    /// # use blahaj::{ Sharks, Share };
     /// # use rand_chacha::rand_core::SeedableRng;
     /// # let sharks = Sharks(3);
     /// // Obtain an iterator over the shares for secret [1, 2]
@@ -106,7 +106,7 @@ impl Sharks {
     ///
     /// Example:
     /// ```
-    /// # use sharks::{ Sharks, Share };
+    /// # use blahaj::{ Sharks, Share };
     /// # let sharks = Sharks(3);
     /// // Obtain an iterator over the shares for secret [1, 2]
     /// let dealer = sharks.dealer(&[1, 2]);
@@ -124,7 +124,7 @@ impl Sharks {
     ///
     /// Example:
     /// ```
-    /// # use sharks::{ Sharks, Share };
+    /// # use blahaj::{ Sharks, Share };
     /// # use rand_chacha::rand_core::SeedableRng;
     /// # let sharks = Sharks(3);
     /// # let mut rng = rand_chacha::ChaCha8Rng::from_seed([0x90; 32]);
@@ -143,23 +143,27 @@ impl Sharks {
         T: IntoIterator<Item = &'a Share>,
         T::IntoIter: Iterator<Item = &'a Share>,
     {
-        let (keys, shares) = shares
+        let mut share_length: Option<usize> = None;
-            .into_iter()
+        let mut keys: HashSet<u8> = HashSet::new();
-            .map(|s| {
+        let mut values: Vec<Share> = Vec::new();
-                (
-                    s.x.0,
-                    Share {
-                        x: s.x,
-                        y: s.y.clone(),
-                    },
-                )
-            })
-            .unzip::<u8, Share, HashSet<u8>, Vec<Share>>();
 
-        if keys.len() < self.0 as usize {
+        for share in shares.into_iter() {
+            if share_length.is_none() {
+                share_length = Some(share.y.len());
+            }
+
+            if Some(share.y.len()) != share_length {
+                return Err("All shares must have the same length");
+            } else {
+                keys.insert(share.x.0);
+                values.push(share.clone());
+            }
+        }
+
+        if keys.is_empty() || (keys.len() < self.0 as usize) {
             Err("Not enough shares to recover original secret")
         } else {
-            Ok(math::interpolate(shares.as_slice()))
+            Ok(math::interpolate(values.as_slice()))
         }
     }
 }
@@ -197,7 +201,7 @@ mod tests {
         let sharks = Sharks(255);
         let mut shares: Vec<Share> = sharks.make_shares(&[1]).take(255).collect();
         shares[1] = Share {
-            x: shares[0].x,
+            x: shares[0].x.clone(),
             y: shares[0].y.clone(),
         };
         let secret = sharks.recover(&shares);

src/math.rs

@@ -20,9 +20,9 @@ pub fn interpolate(shares: &[Share]) -> Vec<u8> {
                     shares
                         .iter()
                         .filter(|s_j| s_j.x != s_i.x)
-                        .map(|s_j| s_j.x / (s_j.x - s_i.x))
+                        .map(|s_j| s_j.x.clone() / (s_j.x.clone() - s_i.x.clone()))
                         .product::<GF256>()
-                        * s_i.y[s]
+                        * s_i.y[s].clone()
                 })
                 .sum::<GF256>()
                 .0
@@ -30,12 +30,12 @@ pub fn interpolate(shares: &[Share]) -> Vec<u8> {
         .collect()
 }
 
-// Generates `k` polynomial coefficients, being the last one `s` and the others randomly generated between `[1, 255]`.
+// Generates `k` polynomial coefficients, being the last one `s` and the others randomly generated between `[0, 255]`.
 // Coefficient degrees go from higher to lower in the returned vector order.
 pub fn random_polynomial<R: rand::Rng>(s: GF256, k: u8, rng: &mut R) -> Vec<GF256> {
     let k = k as usize;
     let mut poly = Vec::with_capacity(k);
-    let between = Uniform::new_inclusive(1, 255);
+    let between = Uniform::new_inclusive(0, 255);
 
     for _ in 1..k {
         poly.push(GF256(between.sample(rng)));
@@ -50,11 +50,14 @@ pub fn random_polynomial<R: rand::Rng>(s: GF256, k: u8, rng: &mut R) -> Vec<GF25
 // Each polynomial corresponds to one byte chunk of the original secret.
 // The iterator will start at `x = 1` and end at `x = 255`.
 pub fn get_evaluator(polys: Vec<Vec<GF256>>) -> impl Iterator<Item = Share> {
-    (1..=u8::max_value()).map(GF256).map(move |x| Share {
+    (1..=u8::MAX).map(GF256).map(move |x| Share {
-        x,
+        x: x.clone(),
         y: polys
             .iter()
-            .map(|p| p.iter().fold(GF256(0), |acc, c| acc * x + *c))
+            .map(|p| {
+                p.iter()
+                    .fold(GF256(0), |acc, c| acc * x.clone() + c.clone())
+            })
             .collect(),
     })
 }
@@ -76,7 +79,7 @@ mod tests {
     #[test]
     fn evaluator_works() {
         let iter = get_evaluator(vec![vec![GF256(3), GF256(2), GF256(5)]]);
-        let values: Vec<_> = iter.take(2).map(|s| (s.x, s.y)).collect();
+        let values: Vec<_> = iter.take(2).map(|s| (s.x.clone(), s.y.clone())).collect();
         assert_eq!(
             values,
             vec![(GF256(1), vec![GF256(4)]), (GF256(2), vec![GF256(13)])]

src/share.rs

@@ -2,11 +2,18 @@ use alloc::vec::Vec;
 
 use super::field::GF256;
 
+#[cfg(feature = "fuzzing")]
+use arbitrary::Arbitrary;
+
+#[cfg(feature = "zeroize_memory")]
+use zeroize::Zeroize;
+
 /// A share used to reconstruct the secret. Can be serialized to and from a byte array.
 ///
 /// Usage example:
 /// ```
-/// use sharks::{Sharks, Share};
+/// use blahaj::{Sharks, Share};
+/// use core::convert::TryFrom;
 /// # use rand_chacha::rand_core::SeedableRng;
 /// # fn send_to_printer(_: Vec<u8>) {}
 /// # fn ask_shares() -> Vec<Vec<u8>> {vec![vec![1, 2], vec![2, 3], vec![3, 4]]}
@@ -23,9 +30,12 @@ use super::field::GF256;
 ///
 /// // Get share bytes from an external source and recover secret
 /// let shares_bytes: Vec<Vec<u8>> = ask_shares();
-/// let shares: Vec<Share> = shares_bytes.iter().map(|s| Share::from(s.as_slice())).collect();
+/// let shares: Vec<Share> = shares_bytes.iter().map(|s| Share::try_from(s.as_slice()).unwrap()).collect();
 /// let secret = sharks.recover(&shares).unwrap();
 #[derive(Clone)]
+#[cfg_attr(feature = "fuzzing", derive(Arbitrary, Debug))]
+#[cfg_attr(feature = "zeroize_memory", derive(Zeroize))]
+#[cfg_attr(feature = "zeroize_memory", zeroize(drop))]
 pub struct Share {
     pub x: GF256,
     pub y: Vec<GF256>,
@@ -42,11 +52,17 @@ impl From<&Share> for Vec<u8> {
 }
 
 /// Obtains a `Share` instance from a byte slice
-impl From<&[u8]> for Share {
+impl core::convert::TryFrom<&[u8]> for Share {
-    fn from(s: &[u8]) -> Share {
+    type Error = &'static str;
-        let x = GF256(s[0]);
+
-        let y = s[1..].iter().map(|p| GF256(*p)).collect();
+    fn try_from(s: &[u8]) -> Result<Share, Self::Error> {
-        Share { x, y }
+        if s.len() < 2 {
+            Err("A Share must be at least 2 bytes long")
+        } else {
+            let x = GF256(s[0]);
+            let y = s[1..].iter().map(|p| GF256(*p)).collect();
+            Ok(Share { x, y })
+        }
     }
 }
 
@@ -54,6 +70,7 @@ impl From<&[u8]> for Share {
 mod tests {
     use super::{Share, GF256};
     use alloc::{vec, vec::Vec};
+    use core::convert::TryFrom;
 
     #[test]
     fn vec_from_share_works() {
@@ -68,7 +85,7 @@ mod tests {
     #[test]
     fn share_from_u8_slice_works() {
         let bytes = [1, 2, 3];
-        let share = Share::from(&bytes[..]);
+        let share = Share::try_from(&bytes[..]).unwrap();
         assert_eq!(share.x, GF256(1));
         assert_eq!(share.y, vec![GF256(2), GF256(3)]);
     }