diff --git a/Cargo.toml b/Cargo.toml
index 1d50531..e7a6788 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,7 +1,7 @@
 [package]
 edition = "2021"
 name = "gosh_bls_lib"
-version = "0.3.1"
+version = "0.4.0"
 
 [profile.profiling]
 debug = 1
@@ -34,6 +34,8 @@ hex = "0.4.3"
 rand = "0.7"
 rand_chacha = "0.2"
 tvm_types = { git = "https://github.com/tvmlabs/tvm-types", tag = "3.0.1" }
+serde = { version = "1.0.197", features = ["derive"] }
+serde_json = "1.0.117"
 
 [[bin]]
 name = "bls_keypair_gen"
diff --git a/src/bin/bls_keypair_gen.rs b/src/bin/bls_keypair_gen.rs
index ac35091..0b75a7a 100644
--- a/src/bin/bls_keypair_gen.rs
+++ b/src/bin/bls_keypair_gen.rs
@@ -4,35 +4,73 @@ use clap::Parser;
 use gosh_bls_lib::bls::gen_bls_key_pair;
 use gosh_bls_lib::bls::gen_bls_key_pair_based_on_key_material;
 use gosh_bls_lib::bls::BLS_SECRET_KEY_LEN;
+use gosh_bls_lib::serde_bls::BLSKeyPair;
+
+const DEFAULT_FILE_STEM: &str = "bls_";
+const FILE_EXTENSION: &str = ".keys.json";
 
 #[derive(Parser)]
 #[command(version, about, long_about = None)]
 struct Args {
-    /// Hex string with 32 bytes of key material for bls
+    /// Hex string with 32 bytes of key material
     #[arg(short, long)]
     key_material: Option<String>,
+    /// Number of key pairs that should be generated
+    #[arg(short, long, conflicts_with = "key_material")]
+    number: Option<u32>,
+    /// Output directory for generated keys (use only for generating several keys)
+    #[arg(short, long, conflicts_with = "path", requires = "number")]
+    output_dir: Option<String>,
+    /// Output file path (use only for generating a single key)
+    #[arg(short, long, conflicts_with_all = ["output_dir", "number"])]
+    path: Option<String>,
+    /// Output file stem (used to generate several files: <stem><i>.keys.json
+    #[arg(long, conflicts_with = "path", requires = "number")]
+    output_stem: Option<String>,
 }
 
-fn main() {
+fn main() -> anyhow::Result<()> {
     let args: Args = Args::parse();
 
-    let (public, secret) = if let Some(key_material) = args.key_material {
+    // Generate first key pair, that will be used as seed in case of generating several keys
+    let first_key = BLSKeyPair::from(if let Some(key_material) = args.key_material {
         let mut secret_key = [0_u8; BLS_SECRET_KEY_LEN];
         hex::decode_to_slice(key_material.trim_start_matches("0x"), &mut secret_key)
-            .expect("Failed to decode secret key from hex");
+            .map_err(|e| anyhow::format_err!("Failed to decode secret key from hex: {e}"))?;
 
         gen_bls_key_pair_based_on_key_material(&secret_key)
-            .expect("Failed to generate BLS key pair")
+            .map_err(|e| anyhow::format_err!("Failed to generate BLS key pair: {e}"))?
     } else {
-        gen_bls_key_pair().expect("Failed to generate BLS key pair")
-    };
-
-    println!(
-        r#"{{
-  "public": "{}",
-  "secret": "{}"
-}}"#,
-        hex::encode(public),
-        hex::encode(secret)
-    );
+        gen_bls_key_pair()
+            .map_err(|e| anyhow::format_err!("Failed to generate BLS key pair: {e}"))?
+    });
+
+    if let Some(path) = args.path {
+        return first_key.save_to_file(path);
+    }
+    if let Some(number) = args.number {
+        let file_stem = args.output_stem.unwrap_or(DEFAULT_FILE_STEM.to_string());
+        let output_dir = args.output_dir.unwrap_or(".".to_string());
+        if !std::path::Path::new(&output_dir).exists() {
+            std::fs::create_dir_all(&output_dir)?;
+        }
+        let full_path_stem = format!("{}/{}", output_dir.trim_end_matches('/'), file_stem);
+
+        let path = format!("{}{}{}", full_path_stem, 0, FILE_EXTENSION);
+        first_key.save_to_file(path)?;
+
+        for i in 1..number {
+            let key_pair = BLSKeyPair::from(
+                gen_bls_key_pair()
+                    .map_err(|e| anyhow::format_err!("Failed to generate BLS key pair: {e}"))?,
+            );
+            let path = format!("{}{}{}", full_path_stem, i, FILE_EXTENSION);
+            key_pair.save_to_file(path)?;
+        }
+        return Ok(());
+    }
+
+    println!("{}", first_key.to_string()?);
+
+    Ok(())
 }
diff --git a/src/lib.rs b/src/lib.rs
index a7884e6..9658276 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1 +1,2 @@
 pub mod bls;
+pub mod serde_bls;
diff --git a/src/serde_bls.rs b/src/serde_bls.rs
new file mode 100644
index 0000000..5e85805
--- /dev/null
+++ b/src/serde_bls.rs
@@ -0,0 +1,45 @@
+use serde::Serialize;
+use std::path::Path;
+
+use crate::bls::BLS_PUBLIC_KEY_LEN;
+use crate::bls::BLS_SECRET_KEY_LEN;
+
+pub struct BLSKeyPair {
+    pub public: [u8; BLS_PUBLIC_KEY_LEN],
+    pub secret: [u8; BLS_SECRET_KEY_LEN],
+}
+
+#[derive(Serialize)]
+struct WrappedBLSKeyPair {
+    public: String,
+    secret: String,
+}
+
+impl WrappedBLSKeyPair {
+    pub fn new(key_pair: &BLSKeyPair) -> Self {
+        WrappedBLSKeyPair {
+            public: hex::encode(key_pair.public),
+            secret: hex::encode(key_pair.secret),
+        }
+    }
+}
+
+impl BLSKeyPair {
+    pub fn from(data: ([u8; BLS_PUBLIC_KEY_LEN], [u8; BLS_SECRET_KEY_LEN])) -> Self {
+        Self {
+            public: data.0,
+            secret: data.1,
+        }
+    }
+
+    pub fn to_string(&self) -> anyhow::Result<String> {
+        let wrapped = WrappedBLSKeyPair::new(self);
+        serde_json::to_string_pretty(&wrapped)
+            .map_err(|e| anyhow::format_err!("Failed to serialize BLSKeyPair: {e}"))
+    }
+
+    pub fn save_to_file(&self, path: impl AsRef<Path>) -> anyhow::Result<()> {
+        std::fs::write(path, self.to_string()?)
+            .map_err(|e| anyhow::format_err!("Failed to save BLSKetPait: {e}"))
+    }
+}