diff --git a/Cargo.lock b/Cargo.lock
index b4757eab..571f5199 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -390,6 +390,18 @@ version = "2.6.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b048fb63fd8b5923fc5aa7b340d8e156aec7ec02f0c78fa8a6ddc2613f6f71de"
 
+[[package]]
+name = "bitvec"
+version = "1.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1bc2832c24239b0141d5674bb9174f9d68a8b5b3f2753311927c172ca46f7e9c"
+dependencies = [
+ "funty",
+ "radium",
+ "tap",
+ "wyz",
+]
+
 [[package]]
 name = "block-buffer"
 version = "0.10.4"
@@ -1021,6 +1033,12 @@ dependencies = [
  "winapi",
 ]
 
+[[package]]
+name = "funty"
+version = "2.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e6d5a32815ae3f33302d95fdcb2ce17862f8c65363dcfd29360480ba1001fc9c"
+
 [[package]]
 name = "futures"
 version = "0.3.31"
@@ -1210,6 +1228,12 @@ dependencies = [
  "crunchy",
 ]
 
+[[package]]
+name = "hamming"
+version = "0.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "65043da274378d68241eb9a8f8f8aa54e349136f7b8e12f63e3ef44043cc30e1"
+
 [[package]]
 name = "hashbrown"
 version = "0.12.3"
@@ -2503,6 +2527,12 @@ dependencies = [
  "proc-macro2",
 ]
 
+[[package]]
+name = "radium"
+version = "0.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dc33ff2d4973d518d823d61aa239014831e521c75da58e3df4840d3f47749d09"
+
 [[package]]
 name = "rand"
 version = "0.8.5"
@@ -3131,6 +3161,12 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "tap"
+version = "1.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "55937e1799185b12863d447f42597ed69d9928686b8d88a1df17376a097d8369"
+
 [[package]]
 name = "tempfile"
 version = "3.14.0"
@@ -3426,8 +3462,10 @@ checksum = "1fc81956842c57dac11422a97c3b8195a1ff727f06e85c84ed2e8aa277c9a0fd"
 name = "uplc"
 version = "1.1.7"
 dependencies = [
+ "bitvec",
  "blst",
  "cryptoxide",
+ "hamming",
  "hex",
  "indexmap 1.9.3",
  "indoc",
@@ -3852,6 +3890,15 @@ version = "0.5.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1e9df38ee2d2c3c5948ea468a8406ff0db0b29ae1ffde1bcf20ef305bcc95c51"
 
+[[package]]
+name = "wyz"
+version = "0.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "05f360fc0b24296329c78fda852a1e9ae82de9cf7b27dae4b7f62f118f77b9ed"
+dependencies = [
+ "tap",
+]
+
 [[package]]
 name = "xdg"
 version = "2.5.2"
diff --git a/crates/uplc/Cargo.toml b/crates/uplc/Cargo.toml
index 432c7b69..9073aa43 100644
--- a/crates/uplc/Cargo.toml
+++ b/crates/uplc/Cargo.toml
@@ -33,6 +33,8 @@ strum_macros = "0.24.3"
 thiserror = "1.0.39"
 blst = "0.3.11"
 once_cell = "1.18.0"
+hamming = "0.1.3"
+bitvec = "1.0.1"
 
 [target.'cfg(not(target_family="wasm"))'.dependencies]
 secp256k1 = { version = "0.26.0" }
diff --git a/crates/uplc/src/machine/runtime.rs b/crates/uplc/src/machine/runtime.rs
index 216b276c..bc44267f 100644
--- a/crates/uplc/src/machine/runtime.rs
+++ b/crates/uplc/src/machine/runtime.rs
@@ -9,8 +9,9 @@ use crate::{
     machine::value::integer_log2,
     plutus_data_to_bytes,
 };
+use bitvec::{order::Lsb0, vec::BitVec};
 use itertools::Itertools;
-use num_bigint::{BigInt, Sign};
+use num_bigint::BigInt;
 use num_integer::Integer;
 use num_traits::{FromPrimitive, Signed, Zero};
 use once_cell::sync::Lazy;
@@ -1664,34 +1665,62 @@ impl DefaultFunction {
 
                 let byte_length = bytes.len();
 
-                if BigInt::from_usize(byte_length).unwrap() * 8 < shift.abs() {
+                if BigInt::from_usize(byte_length).unwrap() * 8 <= shift.abs() {
                     let mut new_vec = vec![];
 
                     new_vec.resize(byte_length, 0);
                     return Ok(Value::byte_string(new_vec));
                 }
 
-                let bytes = BigInt::from_bytes_be(Sign::NoSign, bytes);
-
                 let is_shl = shift >= &0.into();
 
-                let bytes = if is_shl {
-                    bytes << usize::try_from(shift.abs()).unwrap()
-                } else {
-                    bytes >> usize::try_from(shift.abs()).unwrap()
-                }
-                .to_bytes_be()
-                .1
-                .into_iter()
-                .take(byte_length)
-                .collect_vec();
+                let mut bv = BitVec::<u8, Lsb0>::from_vec(bytes.clone());
 
-                Ok(Value::byte_string(bytes))
+                if is_shl {
+                    bv.shift_left(usize::try_from(shift.abs()).unwrap());
+                } else {
+                    bv.shift_right(usize::try_from(shift.abs()).unwrap());
+                }
+
+                Ok(Value::byte_string(bv.into_vec()))
+            }
+            DefaultFunction::RotateByteString => {
+                let bytes = args[0].unwrap_byte_string()?;
+                let shift = args[1].unwrap_integer()?;
+
+                let byte_length = bytes.len();
+
+                let shift = shift % byte_length;
+
+                let mut bv = BitVec::<u8, Lsb0>::from_vec(bytes.clone());
+
+                bv.rotate_right(usize::try_from(shift).unwrap());
+
+                Ok(Value::byte_string(bv.into_vec()))
+            }
+            DefaultFunction::CountSetBits => {
+                let bytes = args[0].unwrap_byte_string()?;
+
+                Ok(Value::integer(hamming::weight(bytes).into()))
             }
-            DefaultFunction::RotateByteString => todo!(),
-            DefaultFunction::CountSetBits => todo!(),
             DefaultFunction::FindFirstSetBit => todo!(),
-            DefaultFunction::Ripemd_160 => todo!(),
+            DefaultFunction::Ripemd_160 => {
+                use cryptoxide::{digest::Digest, ripemd160::Ripemd160};
+
+                let arg1 = args[0].unwrap_byte_string()?;
+
+                let mut hasher = Ripemd160::new();
+
+                hasher.input(arg1);
+
+                let mut bytes = vec![0; hasher.output_bytes()];
+
+                hasher.result(&mut bytes);
+
+                let value = Value::byte_string(bytes);
+
+                Ok(value)
+            }
             DefaultFunction::ExpModInteger => todo!(),
         }
     }