diff --git a/Cargo.lock b/Cargo.lock
index 62f9f5a..163fc58 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2,6 +2,12 @@
 # It is not intended for manual editing.
 version = 3
 
+[[package]]
+name = "arrayvec"
+version = "0.5.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "23b62fc65de8e4e7f52534fb52b0f3ed04746ae267519eef2a83941e8085068b"
+
 [[package]]
 name = "arrayvec"
 version = "0.7.2"
@@ -14,6 +20,16 @@ version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d468802bab17cbc0cc575e9b053f41e72aa36bfa6b7f55e3529ffa43161b97fa"
 
+[[package]]
+name = "bitvec"
+version = "0.17.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "41262f11d771fd4a61aa3ce019fca363b4b6c282fca9da2a31186d3965a47a5c"
+dependencies = [
+ "either",
+ "radium 0.3.0",
+]
+
 [[package]]
 name = "bitvec"
 version = "1.0.0"
@@ -21,11 +37,17 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1489fcb93a5bb47da0462ca93ad252ad6af2145cce58d10d46a83931ba9f016b"
 dependencies = [
  "funty",
- "radium",
+ "radium 0.7.0",
  "tap",
  "wyz",
 ]
 
+[[package]]
+name = "byte-slice-cast"
+version = "0.3.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b0a5e3906bcbf133e33c1d4d95afc664ad37fbdb9f6568d8043e7ea8c27d93d3"
+
 [[package]]
 name = "byte-slice-cast"
 version = "1.2.1"
@@ -56,6 +78,12 @@ version = "0.2.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7a81dae078cea95a014a339291cec439d2f232ebe854a9d672b796c6afafa9b7"
 
+[[package]]
+name = "either"
+version = "1.6.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e78d4f1cc4ae33bbfc157ed5d5a5ef3bc29227303d595861deb238fcec4e9457"
+
 [[package]]
 name = "ethbloom"
 version = "0.12.1"
@@ -90,7 +118,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "cfcf0ed7fe52a17a03854ec54a9f76d6d84508d1c0e66bc1793301c73fc8493c"
 dependencies = [
  "byteorder",
- "rand",
+ "rand 0.8.5",
  "rustc-hex",
  "static_assertions",
 ]
@@ -101,6 +129,17 @@ version = "2.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e6d5a32815ae3f33302d95fdcb2ce17862f8c65363dcfd29360480ba1001fc9c"
 
+[[package]]
+name = "getrandom"
+version = "0.1.16"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8fc3cb4d91f53b50155bdcfd23f6a4c39ae1969c2ae85982b135750cccaf5fce"
+dependencies = [
+ "cfg-if",
+ "libc",
+ "wasi 0.9.0+wasi-snapshot-preview1",
+]
+
 [[package]]
 name = "getrandom"
 version = "0.2.6"
@@ -109,7 +148,7 @@ checksum = "9be70c98951c83b8d2f8f60d7065fa6d5146873094452a1008da8c2f1e4205ad"
 dependencies = [
  "cfg-if",
  "libc",
- "wasi",
+ "wasi 0.10.2+wasi-snapshot-preview1",
 ]
 
 [[package]]
@@ -124,7 +163,7 @@ version = "0.6.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ba6a270039626615617f3f36d15fc827041df3b78c439da2cadfa47455a77f2f"
 dependencies = [
- "parity-scale-codec",
+ "parity-scale-codec 3.1.2",
 ]
 
 [[package]]
@@ -156,12 +195,27 @@ dependencies = [
  "syn",
 ]
 
+[[package]]
+name = "itertools"
+version = "0.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "284f18f85651fe11e8a991b2adb42cb078325c996ed026d994719efcfca1d54b"
+dependencies = [
+ "either",
+]
+
 [[package]]
 name = "libc"
 version = "0.2.126"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "349d5a591cd28b49e1d1037471617a32ddcda5731b99419008085f72d5a53836"
 
+[[package]]
+name = "no-std-compat"
+version = "0.4.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b93853da6d84c2e3c7d730d6473e8817692dd89be387eb01b94d7f108ecb5b8c"
+
 [[package]]
 name = "num-traits"
 version = "0.2.15"
@@ -171,15 +225,27 @@ dependencies = [
  "autocfg",
 ]
 
+[[package]]
+name = "parity-scale-codec"
+version = "1.3.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a4b26b16c7687c3075982af47719e481815df30bc544f7a6690763a25ca16e9d"
+dependencies = [
+ "arrayvec 0.5.2",
+ "bitvec 0.17.4",
+ "byte-slice-cast 0.3.5",
+ "serde",
+]
+
 [[package]]
 name = "parity-scale-codec"
 version = "3.1.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e8b44461635bbb1a0300f100a841e571e7d919c81c73075ef5d152ffdb521066"
 dependencies = [
- "arrayvec",
- "bitvec",
- "byte-slice-cast",
+ "arrayvec 0.7.2",
+ "bitvec 1.0.0",
+ "byte-slice-cast 1.2.1",
  "impl-trait-for-tuples",
  "parity-scale-codec-derive",
  "serde",
@@ -250,12 +316,31 @@ dependencies = [
  "proc-macro2",
 ]
 
+[[package]]
+name = "radium"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "def50a86306165861203e7f84ecffbbdfdea79f0e51039b33de1e952358c47ac"
+
 [[package]]
 name = "radium"
 version = "0.7.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "dc33ff2d4973d518d823d61aa239014831e521c75da58e3df4840d3f47749d09"
 
+[[package]]
+name = "rand"
+version = "0.7.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6a6b1679d49b24bbfe0c803429aa1874472f50d9b363131f0e89fc356b544d03"
+dependencies = [
+ "getrandom 0.1.16",
+ "libc",
+ "rand_chacha 0.2.2",
+ "rand_core 0.5.1",
+ "rand_hc",
+]
+
 [[package]]
 name = "rand"
 version = "0.8.5"
@@ -263,8 +348,18 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "34af8d1a0e25924bc5b7c43c079c942339d8f0a8b57c39049bef581b46327404"
 dependencies = [
  "libc",
- "rand_chacha",
- "rand_core",
+ "rand_chacha 0.3.1",
+ "rand_core 0.6.3",
+]
+
+[[package]]
+name = "rand_chacha"
+version = "0.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f4c8ed856279c9737206bf725bf36935d8666ead7aa69b52be55af369d193402"
+dependencies = [
+ "ppv-lite86",
+ "rand_core 0.5.1",
 ]
 
 [[package]]
@@ -274,7 +369,16 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e6c10a63a0fa32252be49d21e7709d4d4baf8d231c2dbce1eaa8141b9b127d88"
 dependencies = [
  "ppv-lite86",
- "rand_core",
+ "rand_core 0.6.3",
+]
+
+[[package]]
+name = "rand_core"
+version = "0.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "90bde5296fc891b0cef12a6d03ddccc162ce7b2aff54160af9338f8d40df6d19"
+dependencies = [
+ "getrandom 0.1.16",
 ]
 
 [[package]]
@@ -283,7 +387,16 @@ version = "0.6.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d34f1408f55294453790c48b2f1ebbb1c5b4b7563eb1f418bcfcfdbb06ebb4e7"
 dependencies = [
- "getrandom",
+ "getrandom 0.2.6",
+]
+
+[[package]]
+name = "rand_hc"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ca3129af7b92a17112d59ad498c6f81eaf463253766b90396d39ea7a39d6613c"
+dependencies = [
+ "rand_core 0.5.1",
 ]
 
 [[package]]
@@ -376,6 +489,7 @@ dependencies = [
  "ethereum-types",
  "num-traits",
  "paste",
+ "zkp-u256",
 ]
 
 [[package]]
@@ -396,6 +510,12 @@ version = "1.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d22af068fba1eb5edcb4aea19d382b2a3deb4c8f9d475c589b6ada9e0fd493ee"
 
+[[package]]
+name = "wasi"
+version = "0.9.0+wasi-snapshot-preview1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cccddf32554fecc6acb585f82a32a72e28b48f8c4c1883ddfeeeaa96f7d8e519"
+
 [[package]]
 name = "wasi"
 version = "0.10.2+wasi-snapshot-preview1"
@@ -410,3 +530,19 @@ checksum = "30b31594f29d27036c383b53b59ed3476874d518f0efb151b27a4c275141390e"
 dependencies = [
  "tap",
 ]
+
+[[package]]
+name = "zkp-u256"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f9931b419a40ffca971d538c4b5edca60d1d82d77fd6bce73fb4bcb9639776c4"
+dependencies = [
+ "crunchy",
+ "hex",
+ "itertools",
+ "no-std-compat",
+ "num-traits",
+ "parity-scale-codec 1.3.7",
+ "rand 0.7.3",
+ "serde",
+]
diff --git a/Cargo.toml b/Cargo.toml
index a4a6123..8c6bdda 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -9,6 +9,7 @@ edition = "2021"
 ethereum-types = "0.13.1"
 num-traits = "0.2.15"
 paste = "1.0.7"
+zkp-u256 = "0.2.1"
 
 [profile.production]
 incremental = false
diff --git a/src/lib.rs b/src/lib.rs
index df17f32..dd77c01 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -9,7 +9,7 @@ fn fib<N: Number>(times: u32) -> N {
 
     for _ in 0..times {
         buffer = last;
-        last = current;
+        last = current.clone();
         current = current.overflowing_add(buffer);
     }
 
@@ -21,8 +21,8 @@ fn three_n_one<N: Number>(start: u32) -> N {
     let mut current = N::from(start);
 
     while current != N::from(1) {
-        if current % N::from(2) == N::from(0) {
-            current = current / N::from(2);
+        if current.clone() % N::from(2) == N::from(0) {
+            current = current.clone() / N::from(2);
         } else {
             current = current * N::from(3) + N::from(1);
         }
@@ -32,7 +32,7 @@ fn three_n_one<N: Number>(start: u32) -> N {
 }
 
 trait Number:
-    Copy
+    Clone
     + PartialEq
     + std::ops::Div<Output = Self>
     + std::ops::Mul<Output = Self>
@@ -72,6 +72,15 @@ macro_rules! impl_num_eth {
     };
 }
 
+impl Number for zkp_u256::U256 {
+    fn overflowing_add(self, rhs: Self) -> Self {
+        self + rhs
+    }
+    fn from(f: u32) -> Self {
+        <Self as From<u32>>::from(f)
+    }
+}
+
 impl_num_eth!(ethereum_types::U64);
 impl_num_eth!(ethereum_types::U128);
 impl_num_eth!(ethereum_types::U256);
@@ -125,6 +134,10 @@ mod fib {
         impl_fib!(u128);
         impl_fib!(u256);
     }
+    mod zkp {
+        use zkp_u256::U256 as u256;
+        impl_fib!(u256);
+    }
 }
 
 #[cfg(test)]
@@ -146,4 +159,8 @@ mod three_n_one {
         impl_three_n_one!(u128);
         impl_three_n_one!(u256);
     }
+    mod zkp {
+        use zkp_u256::U256 as u256;
+        impl_three_n_one!(u256);
+    }
 }