diff --git a/Cargo.lock b/Cargo.lock
index b4844a4..2c69f78 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -344,7 +344,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "78c8292055d1c1df0cce5d180393dc8cce0abec0a7102adb6c7b1eef6016d60a"
 dependencies = [
  "generic-array",
- "rand_core",
+ "rand_core 0.6.4",
  "typenum",
 ]
 
@@ -542,6 +542,7 @@ dependencies = [
  "cfg-if",
  "libc",
  "r-efi 6.0.0",
+ "rand_core 0.10.1",
 ]
 
 [[package]]
@@ -770,7 +771,7 @@ dependencies = [
  "argon2",
  "chacha20poly1305",
  "chrono",
- "rand",
+ "rand 0.10.2",
  "rmp-serde",
  "serde",
  "serde_json",
@@ -891,7 +892,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "346f04948ba92c43e8469c1ee6736c7563d71012b17d40745260fe106aac2166"
 dependencies = [
  "base64ct",
- "rand_core",
+ "rand_core 0.6.4",
  "subtle",
 ]
 
@@ -977,7 +978,17 @@ checksum = "22f6172bdec972074665ed81ed53b71da00bfc44b65a753cfde883ec4c702a1a"
 dependencies = [
  "libc",
  "rand_chacha",
- "rand_core",
+ "rand_core 0.6.4",
+]
+
+[[package]]
+name = "rand"
+version = "0.10.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c7f5fa3a058cd35567ef9bfa5e75732bee0f9e4c55fa90477bef2dfcdbc4be80"
+dependencies = [
+ "getrandom 0.4.3",
+ "rand_core 0.10.1",
 ]
 
 [[package]]
@@ -987,7 +998,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e6c10a63a0fa32252be49d21e7709d4d4baf8d231c2dbce1eaa8141b9b127d88"
 dependencies = [
  "ppv-lite86",
- "rand_core",
+ "rand_core 0.6.4",
 ]
 
 [[package]]
@@ -999,6 +1010,12 @@ dependencies = [
  "getrandom 0.2.17",
 ]
 
+[[package]]
+name = "rand_core"
+version = "0.10.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "63b8176103e19a2643978565ca18b50549f6101881c443590420e4dc998a3c69"
+
 [[package]]
 name = "ratatui"
 version = "0.30.2"
@@ -1587,7 +1604,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "45e820b97864028eb5069aabf2d90ad7bc279a0ed0292f1306451ce4b91adc13"
 dependencies = [
  "libm",
- "rand",
+ "rand 0.8.7",
  "serde",
  "serde_bytes",
 ]
diff --git a/Cargo.toml b/Cargo.toml
index d101894..733d7bb 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -19,7 +19,7 @@ chacha20poly1305 = "0.10"
 chrono = { version = "0.4", default-features = false, features = ["clock", "serde"] }
 clap = { version = "4.5", features = ["derive"] }
 crossterm = "0.29"
-rand = "0.8"
+rand = { version = "0.10", default-features = false, features = ["sys_rng"] }
 ratatui = { version = "0.30.1", default-features = false, features = ["crossterm_0_29"] }
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0"
diff --git a/crates/mge-core/src/security.rs b/crates/mge-core/src/security.rs
index 4374e58..c5527d1 100644
--- a/crates/mge-core/src/security.rs
+++ b/crates/mge-core/src/security.rs
@@ -19,8 +19,8 @@ use std::str::FromStr;
 use argon2::{Algorithm, Argon2, Params, Version};
 use chacha20poly1305::aead::{Aead, KeyInit, Payload};
 use chacha20poly1305::{XChaCha20Poly1305, XNonce};
-use rand::rngs::OsRng;
-use rand::RngCore;
+use rand::rngs::SysRng;
+use rand::TryRng;
 use serde::{Deserialize, Serialize};
 use zeroize::Zeroize;
 
@@ -40,6 +40,12 @@ const KDF_PARALLELISM: u32 = 1;
 const KEY_CHECK_PLAINTEXT: &[u8] = b"MGE key check v1";
 const KEY_CHECK_AAD: &[u8] = b"mge:key_check:v1";
 
+fn fill_secure_random(bytes: &mut [u8]) -> Result<()> {
+    SysRng
+        .try_fill_bytes(bytes)
+        .map_err(|error| MgeError::Crypto(format!("operating system RNG failed: {error}")))
+}
+
 #[derive(Clone, Copy, Debug, Default, Deserialize, Eq, PartialEq, Serialize)]
 #[serde(rename_all = "snake_case")]
 pub enum SecurityMode {
@@ -168,7 +174,7 @@ pub fn create_security_metadata(passphrase: &str) -> Result<(SecurityMetadata, S
     }
 
     let mut salt = vec![0u8; SALT_LEN];
-    OsRng.fill_bytes(&mut salt);
+    fill_secure_random(&mut salt)?;
     let kdf = KdfMetadata {
         algorithm: KDF_ALGORITHM.to_string(),
         version: KDF_VERSION,
@@ -237,7 +243,7 @@ pub fn unlock_security_metadata(
 
 pub fn encrypt_payload(key: &SessionKey, aad: &[u8], plaintext: &[u8]) -> Result<EncryptedPayload> {
     let mut nonce = vec![0u8; NONCE_LEN];
-    OsRng.fill_bytes(&mut nonce);
+    fill_secure_random(&mut nonce)?;
     let cipher = XChaCha20Poly1305::new_from_slice(key.expose())
         .map_err(|_| MgeError::Crypto("failed to initialize AEAD".to_string()))?;
     let ciphertext = cipher