diff --git a/src/crypto.rs b/src/crypto.rs
index 69389ec..76b78c7 100644
--- a/src/crypto.rs
+++ b/src/crypto.rs
@@ -1,4 +1,5 @@
 use crate::bytes::Bytes;
+use rand::Rng;
 
 pub use openssl::symm::{Cipher, Crypter, Mode};
 
@@ -21,6 +22,14 @@ impl Aes {
         None
     }
 
+    pub fn new_random_128(pad: bool) -> Aes {
+        let key: Vec<u8> = rand::thread_rng()
+            .sample_iter(rand::distributions::Standard)
+            .take(16)
+            .collect();
+        Self::new(&key, pad).unwrap()
+    }
+
     pub fn cbc(&self, data: Vec<u8>, iv: &[u8], mode: Mode) -> Option<Vec<u8>> {
         if (!self.pad) && (data.len() % Self::BLOCK_SIZE != 0) {
             return None;
@@ -106,7 +115,6 @@ impl Aes {
         }
     }
 
-
     fn update(crypter: &mut Crypter, chunk: &[u8], output: &mut [u8]) {
         assert!(
             Self::BLOCK_SIZE
diff --git a/src/main.rs b/src/main.rs
index 7638b03..4c71aef 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -165,9 +165,8 @@ fn q11() {
     let black_box = |mut data: Vec<u8>| -> (bool, Vec<u8>) {
         let mut rng = rand::thread_rng();
         let dist = rand::distributions::Standard;
-        let key: Vec<u8> = rng.sample_iter(&dist).take(16).collect();
         let iv: Vec<u8> = rng.sample_iter(&dist).take(16).collect();
-        let aes = crypto::Aes::new(&key, true).unwrap();
+        let aes = crypto::Aes::new_random_128(true);
         let mut start: Vec<u8> = rng.sample_iter(&dist).take(rng.gen_range(5, 11)).collect();
         let mut end: Vec<u8> = rng.sample_iter(&dist).take(rng.gen_range(5, 11)).collect();
 
@@ -191,12 +190,8 @@ fn q11() {
 
 fn q12() {
     println!("Running q12");
-    let key: Vec<u8> = rand::thread_rng()
-        .sample_iter(rand::distributions::Standard)
-        .take(16)
-        .collect();
     let plaintext: Vec<u8> = Bytes::from_base64("Um9sbGluJyBpbiBteSA1LjAKV2l0aCBteSByYWctdG9wIGRvd24gc28gbXkgaGFpciBjYW4gYmxvdwpUaGUgZ2lybGllcyBvbiBzdGFuZGJ5IHdhdmluZyBqdXN0IHRvIHNheSBoaQpEaWQgeW91IHN0b3A/IE5vLCBJIGp1c3QgZHJvdmUgYnkK").into();
-    let aes = crate::crypto::Aes::new(&key, true).unwrap();
+    let aes = crate::crypto::Aes::new_random_128(true);
 
     let blackbox = |mut data: Vec<u8>| -> Vec<u8> {
         data.append(&mut plaintext.clone());
@@ -252,11 +247,6 @@ fn q12() {
 
 fn q13() {
     println!("Running q13");
-    let key: Vec<u8> = rand::thread_rng()
-        .sample_iter(rand::distributions::Standard)
-        .take(16)
-        .collect();
-
     let parse = |x: &str| -> std::collections::HashMap<String, String> {
         let mut out = std::collections::HashMap::new();
         for pair in x.split(|y| y == '&') {
@@ -275,14 +265,13 @@ fn q13() {
         )
     };
 
+    let aes = crypto::Aes::new_random_128(true);
     let encrypt = |profile: &str| -> Vec<u8> {
         let profile: Vec<u8> = profile.bytes().collect();
-        let aes = crypto::Aes::new(&key, true).unwrap();
         aes.ecb(profile, Mode::Encrypt).unwrap()
     };
 
     let is_admin = |profile: Vec<u8>| -> bool {
-        let aes = crypto::Aes::new(&key, true).unwrap();
         let profile = aes.ecb(profile, Mode::Decrypt).unwrap();
         let profile = String::from_utf8(profile).unwrap();
         parse(&profile)["role"] == "admin"
@@ -306,12 +295,8 @@ fn q13() {
 
 fn q14() {
     println!("Running q14");
-    let key: Vec<u8> = rand::thread_rng()
-        .sample_iter(rand::distributions::Standard)
-        .take(16)
-        .collect();
     let plaintext: Vec<u8> = Bytes::from_base64("Um9sbGluJyBpbiBteSA1LjAKV2l0aCBteSByYWctdG9wIGRvd24gc28gbXkgaGFpciBjYW4gYmxvdwpUaGUgZ2lybGllcyBvbiBzdGFuZGJ5IHdhdmluZyBqdXN0IHRvIHNheSBoaQpEaWQgeW91IHN0b3A/IE5vLCBJIGp1c3QgZHJvdmUgYnkK").into();
-    let aes = crate::crypto::Aes::new(&key, true).unwrap();
+    let aes = crate::crypto::Aes::new_random_128(true);
     let prefix: Vec<u8> = rand::thread_rng()
         .sample_iter(rand::distributions::Standard)
         .take(rand::thread_rng().gen_range(5, 11))