diff --git a/Cargo.lock b/Cargo.lock
index 6fa7f63..fb16f14 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2,19 +2,108 @@
 # It is not intended for manual editing.
 version = 3
 
+[[package]]
+name = "aho-corasick"
+version = "1.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8e60d3430d3a69478ad0993f19238d2df97c507009a52b3c10addcd7f6bcb916"
+dependencies = [
+ "memchr",
+]
+
 [[package]]
 name = "autocfg"
 version = "1.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0c4b4d0bd25bd0b74681c0ad21497610ce1b7c91b1022cd21c80c6fbdd9476b0"
 
+[[package]]
+name = "byteorder"
+version = "1.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1fd0f2584146f6f2ef48085050886acf353beff7305ebd1ae69500e27c67f64b"
+
+[[package]]
+name = "cfg-if"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
+
 [[package]]
 name = "ecc-rust"
 version = "0.1.0"
 dependencies = [
+ "env_logger",
+ "log",
  "num-bigint",
+ "rand",
+]
+
+[[package]]
+name = "env_logger"
+version = "0.10.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4cd405aab171cb85d6735e5c8d9db038c17d3ca007a4d2c25f337935c3d90580"
+dependencies = [
+ "humantime",
+ "is-terminal",
+ "log",
+ "regex",
+ "termcolor",
 ]
 
+[[package]]
+name = "getrandom"
+version = "0.2.15"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c4567c8db10ae91089c99af84c68c38da3ec2f087c3f82960bcdbf3656b6f4d7"
+dependencies = [
+ "cfg-if",
+ "libc",
+ "wasi",
+]
+
+[[package]]
+name = "hermit-abi"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fbf6a919d6cf397374f7dfeeea91d974c7c0a7221d0d0f4f20d859d329e53fcc"
+
+[[package]]
+name = "humantime"
+version = "2.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9a3a5bfb195931eeb336b2a7b4d761daec841b97f947d34394601737a7bba5e4"
+
+[[package]]
+name = "is-terminal"
+version = "0.4.13"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "261f68e344040fbd0edea105bef17c66edf46f984ddb1115b775ce31be948f4b"
+dependencies = [
+ "hermit-abi",
+ "libc",
+ "windows-sys 0.52.0",
+]
+
+[[package]]
+name = "libc"
+version = "0.2.159"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "561d97a539a36e26a9a5fad1ea11a3039a67714694aaa379433e580854bc3dc5"
+
+[[package]]
+name = "log"
+version = "0.4.22"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a7a70ba024b9dc04c27ea2f0c0548feb474ec5c54bba33a7f72f873a39d07b24"
+
+[[package]]
+name = "memchr"
+version = "2.7.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "78ca9ab1a0babb1e7d5695e3530886289c18cf2f87ec19a575a0abdce112e3a3"
+
 [[package]]
 name = "num-bigint"
 version = "0.4.6"
@@ -23,6 +112,7 @@ checksum = "a5e44f723f1133c9deac646763579fdb3ac745e418f2a7af9cd0c431da1f20b9"
 dependencies = [
  "num-integer",
  "num-traits",
+ "rand",
 ]
 
 [[package]]
@@ -42,3 +132,233 @@ checksum = "071dfc062690e90b734c0b2273ce72ad0ffa95f0c74596bc250dcfd960262841"
 dependencies = [
  "autocfg",
 ]
+
+[[package]]
+name = "ppv-lite86"
+version = "0.2.20"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "77957b295656769bb8ad2b6a6b09d897d94f05c41b069aede1fcdaa675eaea04"
+dependencies = [
+ "zerocopy",
+]
+
+[[package]]
+name = "proc-macro2"
+version = "1.0.86"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5e719e8df665df0d1c8fbfd238015744736151d4445ec0836b8e628aae103b77"
+dependencies = [
+ "unicode-ident",
+]
+
+[[package]]
+name = "quote"
+version = "1.0.37"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b5b9d34b8991d19d98081b46eacdd8eb58c6f2b201139f7c5f643cc155a633af"
+dependencies = [
+ "proc-macro2",
+]
+
+[[package]]
+name = "rand"
+version = "0.8.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "34af8d1a0e25924bc5b7c43c079c942339d8f0a8b57c39049bef581b46327404"
+dependencies = [
+ "libc",
+ "rand_chacha",
+ "rand_core",
+]
+
+[[package]]
+name = "rand_chacha"
+version = "0.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e6c10a63a0fa32252be49d21e7709d4d4baf8d231c2dbce1eaa8141b9b127d88"
+dependencies = [
+ "ppv-lite86",
+ "rand_core",
+]
+
+[[package]]
+name = "rand_core"
+version = "0.6.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ec0be4795e2f6a28069bec0b5ff3e2ac9bafc99e6a9a7dc3547996c5c816922c"
+dependencies = [
+ "getrandom",
+]
+
+[[package]]
+name = "regex"
+version = "1.10.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4219d74c6b67a3654a9fbebc4b419e22126d13d2f3c4a07ee0cb61ff79a79619"
+dependencies = [
+ "aho-corasick",
+ "memchr",
+ "regex-automata",
+ "regex-syntax",
+]
+
+[[package]]
+name = "regex-automata"
+version = "0.4.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "38caf58cc5ef2fed281f89292ef23f6365465ed9a41b7a7754eb4e26496c92df"
+dependencies = [
+ "aho-corasick",
+ "memchr",
+ "regex-syntax",
+]
+
+[[package]]
+name = "regex-syntax"
+version = "0.8.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7a66a03ae7c801facd77a29370b4faec201768915ac14a721ba36f20bc9c209b"
+
+[[package]]
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+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9f35bcdf61fd8e7be6caf75f429fdca8beb3ed76584befb503b1569faee373ed"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "unicode-ident",
+]
+
+[[package]]
+name = "termcolor"
+version = "1.4.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "06794f8f6c5c898b3275aebefa6b8a1cb24cd2c6c79397ab15774837a0bc5755"
+dependencies = [
+ "winapi-util",
+]
+
+[[package]]
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+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e91b56cd4cadaeb79bbf1a5645f6b4f8dc5bde8834ad5894a8db35fda9efa1fe"
+
+[[package]]
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+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9c8d87e72b64a3b4db28d11ce29237c246188f4f51057d65a7eab63b7987e423"
+
+[[package]]
+name = "winapi-util"
+version = "0.1.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cf221c93e13a30d793f7645a0e7762c55d169dbb0a49671918a2319d289b10bb"
+dependencies = [
+ "windows-sys 0.59.0",
+]
+
+[[package]]
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+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "282be5f36a8ce781fad8c8ae18fa3f9beff57ec1b52cb3de0789201425d9a33d"
+dependencies = [
+ "windows-targets",
+]
+
+[[package]]
+name = "windows-sys"
+version = "0.59.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1e38bc4d79ed67fd075bcc251a1c39b32a1776bbe92e5bef1f0bf1f8c531853b"
+dependencies = [
+ "windows-targets",
+]
+
+[[package]]
+name = "windows-targets"
+version = "0.52.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9b724f72796e036ab90c1021d4780d4d3d648aca59e491e6b98e725b84e99973"
+dependencies = [
+ "windows_aarch64_gnullvm",
+ "windows_aarch64_msvc",
+ "windows_i686_gnu",
+ "windows_i686_gnullvm",
+ "windows_i686_msvc",
+ "windows_x86_64_gnu",
+ "windows_x86_64_gnullvm",
+ "windows_x86_64_msvc",
+]
+
+[[package]]
+name = "windows_aarch64_gnullvm"
+version = "0.52.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
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+
+[[package]]
+name = "windows_aarch64_msvc"
+version = "0.52.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "09ec2a7bb152e2252b53fa7803150007879548bc709c039df7627cabbd05d469"
+
+[[package]]
+name = "windows_i686_gnu"
+version = "0.52.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8e9b5ad5ab802e97eb8e295ac6720e509ee4c243f69d781394014ebfe8bbfa0b"
+
+[[package]]
+name = "windows_i686_gnullvm"
+version = "0.52.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0eee52d38c090b3caa76c563b86c3a4bd71ef1a819287c19d586d7334ae8ed66"
+
+[[package]]
+name = "windows_i686_msvc"
+version = "0.52.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "240948bc05c5e7c6dabba28bf89d89ffce3e303022809e73deaefe4f6ec56c66"
+
+[[package]]
+name = "windows_x86_64_gnu"
+version = "0.52.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "147a5c80aabfbf0c7d901cb5895d1de30ef2907eb21fbbab29ca94c5b08b1a78"
+
+[[package]]
+name = "windows_x86_64_gnullvm"
+version = "0.52.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "24d5b23dc417412679681396f2b49f3de8c1473deb516bd34410872eff51ed0d"
+
+[[package]]
+name = "windows_x86_64_msvc"
+version = "0.52.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "589f6da84c646204747d1270a2a5661ea66ed1cced2631d546fdfb155959f9ec"
+
+[[package]]
+name = "zerocopy"
+version = "0.7.35"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1b9b4fd18abc82b8136838da5d50bae7bdea537c574d8dc1a34ed098d6c166f0"
+dependencies = [
+ "byteorder",
+ "zerocopy-derive",
+]
+
+[[package]]
+name = "zerocopy-derive"
+version = "0.7.35"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fa4f8080344d4671fb4e831a13ad1e68092748387dfc4f55e356242fae12ce3e"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
diff --git a/Cargo.toml b/Cargo.toml
index c63cff2..5418445 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -10,4 +10,7 @@ version = "0.1.0"
 edition = "2021"
 
 [dependencies]
-num-bigint = "0.4.6"
+num-bigint = { version = "0.4", features = ["rand"] }
+rand = "0.8"
+log = "0.4"
+env_logger = "0.10"
\ No newline at end of file
diff --git a/src/ecdsa.rs b/src/ecdsa.rs
new file mode 100644
index 0000000..b50a0fa
--- /dev/null
+++ b/src/ecdsa.rs
@@ -0,0 +1,222 @@
+use crate::{EllipticCurve, FiniteField, Point};
+use log::{debug, info, warn};
+use num_bigint::{BigUint, RandBigInt};
+use rand::thread_rng;
+
+pub struct ECDSA {
+    curve: EllipticCurve,
+    generator: Point,
+    order: BigUint,
+}
+
+impl ECDSA {
+    pub fn new(curve: EllipticCurve, generator: Point, order: BigUint) -> Self {
+        debug!("Creating new ECDSA instance");
+        assert!(
+            curve.is_on_curve(&generator),
+            "Generator point must be on the curve"
+        );
+        ECDSA {
+            curve,
+            generator,
+            order,
+        }
+    }
+
+    pub fn generate_keypair(&self) -> (BigUint, Point) {
+        debug!("Generating new keypair");
+        let private_key = self.generate_random_private_key();
+        let public_key = self.generate_public_key(&private_key);
+
+        self.validate_public_key(&public_key);
+        info!("Keypair generated successfully");
+        (private_key, public_key)
+    }
+
+    pub fn generate_public_key(&self, private_key: &BigUint) -> Point {
+        debug!("Generating public key from private key");
+        self.curve.mul(&self.generator, private_key)
+    }
+
+    pub fn sign(&self, message: &BigUint, private_key: &BigUint) -> Result<(BigUint, BigUint), &'static str> {
+        self.validate_input(message, private_key)?;
+        debug!("Signing message");
+        let k = self.generate_random_private_key();
+        self.sign_with_k(message, private_key, &k)
+    }
+
+    pub fn verify(
+        &self,
+        message: &BigUint,
+        signature: &(BigUint, BigUint),
+        public_key: &Point,
+    ) -> bool {
+        debug!("Verifying signature");
+        let (r, s) = signature;
+
+        if !self.is_valid_signature(r, s) {
+            return false;
+        }
+
+        let s_inv = FiniteField::inv_mul(s, &self.order);
+        let u1 = FiniteField::mul(message, &s_inv, &self.order);
+        let u2 = FiniteField::mul(r, &s_inv, &self.order);
+        let point = self.calculate_verification_point(&u1, &u2, public_key);
+
+        self.is_signature_valid(point, r)
+    }
+
+    fn validate_input(&self, message: &BigUint, private_key: &BigUint) -> Result<(), &'static str> {
+        if private_key >= &self.order {
+            return Err("Private key must be less than the order of the curve");
+        }
+        if message >= &self.order {
+            return Err("Message must be less than the order of the curve");
+        }
+        Ok(())
+    }
+
+    fn sign_with_k(
+        &self,
+        message: &BigUint,
+        private_key: &BigUint,
+        k: &BigUint,
+    ) -> Result<(BigUint, BigUint), &'static str> {
+        if k >= &self.order {
+            return Err("k must be less than the order of the curve");
+        }
+
+        let r = self.calculate_r(k);
+        let s = self.calculate_s(message, private_key, k, &r);
+
+        info!("Message signed successfully");
+        Ok((r, s))
+    }
+
+    fn calculate_r(&self, k: &BigUint) -> BigUint {
+        match self.curve.mul(&self.generator, k) {
+            Point::Coordinates(x, _) => x,
+            Point::Identity => {
+                warn!("Unexpected point at infinity during signing");
+                panic!("Unexpected point at infinity");
+            }
+        }
+    }
+
+    fn calculate_s(
+        &self,
+        message: &BigUint,
+        private_key: &BigUint,
+        k: &BigUint,
+        r: &BigUint,
+    ) -> BigUint {
+        let s = FiniteField::mul(r, private_key, &self.order);
+        let s = FiniteField::add(message, &s, &self.order);
+        let k_inv = FiniteField::inv_mul(k, &self.order);
+        FiniteField::mul(&s, &k_inv, &self.order)
+    }
+
+    fn is_valid_signature(&self, r: &BigUint, s: &BigUint) -> bool {
+        if r >= &self.order || s >= &self.order {
+            warn!("Invalid signature: r or s is too large");
+            return false;
+        }
+        true
+    }
+
+    fn calculate_verification_point(
+        &self,
+        u1: &BigUint,
+        u2: &BigUint,
+        public_key: &Point,
+    ) -> Point {
+        let u1a = self.curve.mul(&self.generator, u1);
+        let u2b = self.curve.mul(public_key, u2);
+        self.curve.add(&u1a, &u2b)
+    }
+
+    fn is_signature_valid(&self, point: Point, r: &BigUint) -> bool {
+        match point {
+            Point::Coordinates(x, _) => x == *r,
+            Point::Identity => {
+                warn!("Unexpected point at infinity during verification");
+                false
+            }
+        }
+    }
+
+    fn generate_random_private_key(&self) -> BigUint {
+        debug!("Generating random private key");
+        thread_rng().gen_biguint_range(&BigUint::from(1u32), &self.order)
+    }
+
+    fn validate_public_key(&self, public_key: &Point) {
+        assert!(
+            self.curve.is_on_curve(public_key),
+            "Generated public key is not on the curve"
+        );
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use env_logger;
+
+    fn init() {
+        let _ = env_logger::builder().is_test(true).try_init();
+    }
+
+    fn create_test_ecdsa() -> ECDSA {
+        let curve = EllipticCurve {
+            a: BigUint::from(2u32),
+            b: BigUint::from(2u32),
+            p: BigUint::from(17u32),
+        };
+
+        ECDSA::new(
+            curve,
+            Point::Coordinates(BigUint::from(5u32), BigUint::from(1u32)),
+            BigUint::from(19u32),
+        )
+    }
+
+    #[test]
+    fn test_generate_keypair() {
+        init();
+        let ecdsa = create_test_ecdsa();
+        let (private_key, public_key) = ecdsa.generate_keypair();
+        assert!(private_key < ecdsa.order);
+        assert!(
+            ecdsa.curve.is_on_curve(&public_key),
+            "Generated public key is not on the curve"
+        );
+    }
+
+    #[test]
+    fn test_sign_and_verify() {
+        init();
+        let ecdsa = create_test_ecdsa();
+        let (private_key, public_key) = (
+            BigUint::from(7u32),
+            ecdsa.generate_public_key(&BigUint::from(7u32)),
+        );
+        let message = BigUint::from(10u32);
+        let signature = ecdsa.sign_with_k(&message, &private_key, &BigUint::from(18u32)).unwrap();
+        assert!(ecdsa.verify(&message, &signature, &public_key));
+    }
+
+    #[test]
+    fn test_verify_invalid_signature() {
+        init();
+        let ecdsa = create_test_ecdsa();
+        let (private_key, public_key) = (
+            BigUint::from(7u32),
+            ecdsa.generate_public_key(&BigUint::from(7u32)),
+        );
+        let message = BigUint::from(5u32);
+        let mut signature = ecdsa.sign(&message, &private_key).unwrap();
+        signature.1 += BigUint::from(1u32); // Modify the signature to make it invalid
+        assert!(!ecdsa.verify(&message, &signature, &public_key));
+    }
+}
diff --git a/src/lib.rs b/src/lib.rs
index 025092b..0f7ad6a 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -2,9 +2,11 @@ mod curves;
 mod ec;
 mod ff;
 mod point;
+mod ecdsa;
 
 pub use curves::*;
 pub use ec::*;
 pub use ff::*;
 pub use point::*;
+pub use ecdsa::*;