diff --git a/Cargo.lock b/Cargo.lock
index c87cdae..4acf035 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -214,13 +214,14 @@ checksum = "48c757948c5ede0e46177b7add2e67155f70e33c07fea8284df6576da70b3719"
 
 [[package]]
 name = "getrandom"
-version = "0.2.17"
+version = "0.3.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ff2abc00be7fca6ebc474524697ae276ad847ad0a6b3faa4bcb027e9a4614ad0"
+checksum = "899def5c37c4fd7b2664648c28120ecec138e4d395b459e5ca34f9cce2dd77fd"
 dependencies = [
  "cfg-if",
  "libc",
- "wasi",
+ "r-efi",
+ "wasip2",
 ]
 
 [[package]]
@@ -276,15 +277,6 @@ dependencies = [
  "wasm-bindgen",
 ]
 
-[[package]]
-name = "lazy_static"
-version = "1.5.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bbd2bcb4c963f2ddae06a2efc7e9f3591312473c50c6685e1f298068316e66fe"
-dependencies = [
- "spin",
-]
-
 [[package]]
 name = "libc"
 version = "0.2.185"
@@ -305,15 +297,15 @@ checksum = "f8ca58f447f06ed17d5fc4043ce1b10dd205e060fb3ce5b979b8ed8e59ff3f79"
 
 [[package]]
 name = "num-bigint-dig"
-version = "0.8.6"
+version = "0.9.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e661dda6640fad38e827a6d4a310ff4763082116fe217f279885c97f511bb0b7"
+checksum = "a7f9a86e097b0d187ad0e65667c2f58b9254671e86e7dbb78036b16692eae099"
 dependencies = [
- "lazy_static",
  "libm",
  "num-integer",
  "num-iter",
  "num-traits",
+ "once_cell",
  "rand",
  "serde",
  "smallvec",
@@ -430,32 +422,37 @@ dependencies = [
  "proc-macro2",
 ]
 
+[[package]]
+name = "r-efi"
+version = "5.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "69cdb34c158ceb288df11e18b4bd39de994f6657d83847bdffdbd7f346754b0f"
+
 [[package]]
 name = "rand"
-version = "0.8.5"
+version = "0.9.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "34af8d1a0e25924bc5b7c43c079c942339d8f0a8b57c39049bef581b46327404"
+checksum = "44c5af06bb1b7d3216d91932aed5265164bf384dc89cd6ba05cf59a35f5f76ea"
 dependencies = [
- "libc",
  "rand_chacha",
- "rand_core 0.6.4",
+ "rand_core 0.9.5",
 ]
 
 [[package]]
 name = "rand_chacha"
-version = "0.3.1"
+version = "0.9.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e6c10a63a0fa32252be49d21e7709d4d4baf8d231c2dbce1eaa8141b9b127d88"
+checksum = "d3022b5f1df60f26e1ffddd6c66e8aa15de382ae63b3a0c1bfc0e4d3e3f325cb"
 dependencies = [
  "ppv-lite86",
- "rand_core 0.6.4",
+ "rand_core 0.9.5",
 ]
 
 [[package]]
 name = "rand_core"
-version = "0.6.4"
+version = "0.9.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ec0be4795e2f6a28069bec0b5ff3e2ac9bafc99e6a9a7dc3547996c5c816922c"
+checksum = "76afc826de14238e6e8c374ddcc1fa19e374fd8dd986b0d2af0d02377261d83c"
 dependencies = [
  "getrandom",
 ]
@@ -589,12 +586,6 @@ version = "1.15.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "67b1b7a3b5fe4f1376887184045fcf45c69e92af734b7aaddc05fb777b6fbd03"
 
-[[package]]
-name = "spin"
-version = "0.9.8"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6980e8d7511241f8acf4aebddbb1ff938df5eebe98691418c4468d0b72a96a67"
-
 [[package]]
 name = "syn"
 version = "2.0.117"
@@ -653,10 +644,13 @@ dependencies = [
 ]
 
 [[package]]
-name = "wasi"
-version = "0.11.1+wasi-snapshot-preview1"
+name = "wasip2"
+version = "1.0.2+wasi-0.2.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ccf3ec651a847eb01de73ccad15eb7d99f80485de043efb2f370cd654f4ea44b"
+checksum = "9517f9239f02c069db75e65f174b3da828fe5f5b945c4dd26bd25d89c03ebcf5"
+dependencies = [
+ "wit-bindgen",
+]
 
 [[package]]
 name = "wasm-bindgen"
@@ -737,6 +731,12 @@ dependencies = [
  "windows-link",
 ]
 
+[[package]]
+name = "wit-bindgen"
+version = "0.51.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d7249219f66ced02969388cf2bb044a09756a083d0fab1e566056b04d9fbcaa5"
+
 [[package]]
 name = "zerocopy"
 version = "0.8.48"
diff --git a/Cargo.toml b/Cargo.toml
index 744d099..ac98dc5 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -8,7 +8,7 @@ license = "MIT OR Apache-2.0"
 readme = "README.md"
 
 [dependencies]
-num-bigint-dig = { version = "0.8", features = [
+num-bigint-dig = { version = "0.9.1", features = [
     "zeroize",
     "prime",
     "rand",
@@ -16,7 +16,7 @@ num-bigint-dig = { version = "0.8", features = [
 ] }
 num-traits = "0.2"
 num-integer = "0.1"
-rand = "0.8"
+rand = "0.9.3"
 zeroize = { version = "1.8", features = ["derive"] }
 thiserror = "2"
 # Constant-time modular arithmetic for the decryption hot path (SECURITY-2).
diff --git a/src/key.rs b/src/key.rs
index fd637f5..ec70db3 100644
--- a/src/key.rs
+++ b/src/key.rs
@@ -4,7 +4,8 @@
 use num_bigint_dig::{BigUint, ModInverse, RandBigInt};
 use num_integer::Integer;
 use num_traits::{One, Zero};
-use rand::rngs::OsRng;
+use rand::rngs::StdRng;
+use rand::SeedableRng;
 use zeroize::{Zeroize, ZeroizeOnDrop};
 
 use crate::util::l_function;
@@ -214,7 +215,7 @@ impl KeyPair {
             });
         }
 
-        let mut rng = OsRng;
+        let mut rng = StdRng::from_os_rng();
         let p_bits = bit_length / 3;
         let q_bits = bit_length - (2 * p_bits);
 
diff --git a/src/okuchi.rs b/src/okuchi.rs
index 4e22b02..99bf55b 100644
--- a/src/okuchi.rs
+++ b/src/okuchi.rs
@@ -4,7 +4,8 @@
 use num_bigint_dig::{BigUint, RandBigInt};
 use num_integer::Integer;
 use num_traits::{One, Zero};
-use rand::rngs::OsRng;
+use rand::rngs::StdRng;
+use rand::SeedableRng;
 
 use crate::ciphertext::Ciphertext;
 use crate::error::{Error, Result};
@@ -52,7 +53,7 @@ impl Okuchi {
             return Err(Error::PlaintextTooLarge);
         }
 
-        let mut rng = OsRng;
+        let mut rng = StdRng::from_os_rng();
 
         // OU requires gcd(r, n) = 1. With n = p²q the failure probability is
         // ≈ 1/p + 1/q. This is negligible but the protocol is undefined otherwise.
diff --git a/src/util.rs b/src/util.rs
index da4a08a..2fda17e 100644
--- a/src/util.rs
+++ b/src/util.rs
@@ -9,7 +9,8 @@ use crypto_bigint::modular::{BoxedMontyForm, BoxedMontyParams};
 use crypto_bigint::{BoxedUint, Odd};
 use num_bigint_dig::{BigUint, RandPrime};
 use num_traits::One;
-use rand::rngs::OsRng;
+use rand::rngs::StdRng;
+use rand::SeedableRng;
 
 use crate::{Error, Result};
 
@@ -98,6 +99,6 @@ pub fn generate_prime(bits: usize) -> Result<BigUint> {
             "prime bit length must be >= 2".into(),
         ));
     }
-    let mut rng = OsRng;
+    let mut rng = StdRng::from_os_rng();
     Ok(rng.gen_prime(bits)) // gen_prime uses Miller-Rabin internally
 }