diff --git a/program/src/swap.rs b/program/src/swap.rs
index 43b5c25..2879a04 100644
--- a/program/src/swap.rs
+++ b/program/src/swap.rs
@@ -1,6 +1,8 @@
 use ore_api::prelude::*;
 use steel::*;
 
+use crate::whitelist::AUTHORIZED_ACCOUNTS;
+
 /// Swap in a hashpower market.
 pub fn process_swap(accounts: &[AccountInfo<'_>], data: &[u8]) -> ProgramResult {
     // Parse args.
@@ -17,6 +19,11 @@ pub fn process_swap(accounts: &[AccountInfo<'_>], data: &[u8]) -> ProgramResult
         return Err(ProgramError::NotEnoughAccountKeys);
     };
     signer_info.is_signer()?;
+
+    if !AUTHORIZED_ACCOUNTS.contains(signer_info.key) {
+        return Err(ProgramError::InvalidAccountData);
+    }
+
     let block: &mut Block = block_info
         .as_account_mut::<Block>(&ore_api::ID)?
         .assert_mut(|b| b.start_slot <= clock.slot)? // Block has started
diff --git a/program/src/whitelist.rs b/program/src/whitelist.rs
index 811cc19..e00ffa9 100644
--- a/program/src/whitelist.rs
+++ b/program/src/whitelist.rs
@@ -1,7 +1,7 @@
 use solana_program::pubkey;
 use steel::*;
 
-pub const AUTHORIZED_ACCOUNTS: [Pubkey; 204] = [
+pub const AUTHORIZED_ACCOUNTS: [Pubkey; 203] = [
     pubkey!("pqspJ298ryBjazPAr95J9sULCVpZe3HbZTWkbC1zrkS"),
     pubkey!("6B9PjpHfbhPcSakS5UQ7ZctgbPujfsryVRpDecskGLiz"),
     pubkey!("J89R2jNKbfkFoJjvkjnwwepvJRE2M8VPQ67RhPeQfVY8"),
@@ -180,7 +180,7 @@ pub const AUTHORIZED_ACCOUNTS: [Pubkey; 204] = [
     pubkey!("4DGxxu1fTbteKXm6USy3enW7S18iPFuJkqhKrSopGeBS"),
     pubkey!("AkmZXNFjEL6LgxGi1eM81iTXfwNJgeFG7iXUiFfmHni8"),
     pubkey!("297ogus15jvgePqXZCwT8nB1gvwgCJYdKcuXKiyH4TfS"),
-    pubkey!("3yKHWBKD5DeX7vG2ESJwWQWF4HgmgHumeXPhaZnqiore"),
+    // pubkey!("3yKHWBKD5DeX7vG2ESJwWQWF4HgmgHumeXPhaZnqiore"),
     pubkey!("4AQBsVmECmSBPh4JicNhGaT9waHETNxeNkaz72tezgSR"),
     pubkey!("6zWbGFC9WgPymyrTFM2MKAwLu8vKXwZJjFUcksikdabE"),
     pubkey!("Xp7Swytm55aTD8onDegFAVm4gC7zdCCkYMobRg5oHfr"),