diff --git a/aes/src/block/block128.rs b/aes/src/block/block128.rs
index 814c416..eee3c9f 100644
--- a/aes/src/block/block128.rs
+++ b/aes/src/block/block128.rs
@@ -107,7 +107,7 @@ fn parse_radix(s: &str, radix: u32) -> Result<u128, BlockError> {
 }
 
 fn ascii_string_to_u128(s: &str) -> Result<u128, BlockError> {
-    if s.len() > 8 {
+    if s.len() > 16 {
         return Err(BlockError::InvalidByteStringLength(s.len()));
     }
 
diff --git a/cipher-core/src/traits/block_cipher.rs b/cipher-core/src/traits/block_cipher.rs
index dd91a45..7a79773 100644
--- a/cipher-core/src/traits/block_cipher.rs
+++ b/cipher-core/src/traits/block_cipher.rs
@@ -5,7 +5,7 @@ use crate::{CipherAction, CipherError, CipherResult, Output};
 /// Implements the standard encrypt/decrypt interface for block ciphers.
 /// Implementers define `transform_impl` to handle the core algorithm,
 /// while `transform` provides validation and convenience wrappers.
-pub trait BlockCipher: Sized {
+pub trait BlockCipher {
     const BLOCK_SIZE: usize;
 
     fn from_key(key: &[u8]) -> Self;
diff --git a/cipher-factory/src/algorithm.rs b/cipher-factory/src/algorithm.rs
index 9f7ddf6..1dbb7a1 100644
--- a/cipher-factory/src/algorithm.rs
+++ b/cipher-factory/src/algorithm.rs
@@ -1,5 +1,3 @@
-use cipher_core::{BlockCipher, InputBlock};
-use des::Des;
 use std::fmt::Display;
 
 #[cfg_attr(feature = "clap", derive(clap::ValueEnum))]
@@ -9,16 +7,6 @@ pub enum Algorithm {
     Aes,
 }
 
-impl Algorithm {
-    #[must_use]
-    pub fn get_cipher(&self, key: &impl InputBlock) -> impl BlockCipher {
-        match self {
-            Self::Des => Des::from_key(key.as_bytes()),
-            Self::Aes => todo!("Must implement AES first"),
-        }
-    }
-}
-
 impl Display for Algorithm {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         let s = match self {
diff --git a/cipher-factory/src/output.rs b/cipher-factory/src/output.rs
index 6d66a95..1ee6b98 100644
--- a/cipher-factory/src/output.rs
+++ b/cipher-factory/src/output.rs
@@ -18,9 +18,9 @@ impl OutputFormat {
     #[must_use]
     pub fn to_string(&self, value: &Output) -> String {
         match self {
-            Self::Binary => format!("{value:064b}"),
-            Self::Octal => format!("{value:022o}"),
-            Self::Hex => format!("{value:016X}"),
+            Self::Binary => format!("{value:b}"),
+            Self::Octal => format!("{value:o}"),
+            Self::Hex => format!("{value:X}"),
             Self::Text => format!("{value}"),
         }
     }
diff --git a/cli/src/args.rs b/cli/src/args.rs
index 40d94d6..6abd58b 100644
--- a/cli/src/args.rs
+++ b/cli/src/args.rs
@@ -1,7 +1,5 @@
 use cipher_factory::{Algorithm, OperationChoice, OutputFormat};
 use clap::Parser;
-use des::Block64;
-use std::str::FromStr;
 
 #[derive(Debug, Clone, Parser)]
 #[command(version, about, long_about = None)]
@@ -15,12 +13,12 @@ pub struct Args {
     pub algorithm: Algorithm,
 
     /// Key used for encryption/decryption. Can be a string or a path to a file
-    #[arg(short, long, value_parser = Block64::from_str, required = true)]
-    pub key: Block64,
+    #[arg(short, long, required = true)]
+    pub key: String,
 
     /// The text to encrypt/decrypt. Can be a string or a path to a file
-    #[arg(value_name = "TEXT", value_parser = Block64::from_str, required = true)]
-    pub text: Block64,
+    #[arg(value_name = "TEXT", required = true)]
+    pub text: String,
 
     /// Output format for decrypted data
     #[arg(short = 'f', long)]
diff --git a/cli/src/main.rs b/cli/src/main.rs
index 8548557..bc01a55 100644
--- a/cli/src/main.rs
+++ b/cli/src/main.rs
@@ -1,11 +1,15 @@
 mod args;
 
 use crate::args::Args;
+use aes::{Aes, Block128};
 use cipher_core::BlockCipher;
-use cipher_factory::OperationChoice;
+use cipher_factory::{Algorithm, OperationChoice, OutputFormat};
 use clap::Parser;
+use color_eyre::eyre::{Ok, Result};
+use des::{Block64, Des};
+use std::str::FromStr;
 
-fn main() -> color_eyre::Result<()> {
+fn main() -> Result<()> {
     color_eyre::install()?;
     let Args {
         operation,
@@ -15,18 +19,40 @@ fn main() -> color_eyre::Result<()> {
         output_format,
     } = Args::parse();
 
-    match operation {
-        OperationChoice::Encrypt => {
-            let cipher = algorithm.get_cipher(&key);
-            let ciphertext = cipher.encrypt(&text.to_be_bytes())?;
-            println!("{ciphertext:016X}");
+    match algorithm {
+        Algorithm::Des => {
+            let key = Block64::from_str(&key)?;
+            let text = Block64::from_str(&text)?;
+            let cipher = Des::from_key(&key.to_be_bytes());
+            execute_cipher(operation, &cipher, &text.to_be_bytes(), output_format)?;
         }
-        OperationChoice::Decrypt => {
-            let cipher = algorithm.get_cipher(&key);
-            let plaintext = cipher.decrypt(&text.to_be_bytes())?;
-            let output = output_format.unwrap_or_default().to_string(&plaintext);
-            println!("{output}");
+        Algorithm::Aes => {
+            let key = Block128::from_str(&key)?;
+            let text = Block128::from_str(&text)?;
+            let cipher = Aes::from_key(&key.to_be_bytes());
+            execute_cipher(operation, &cipher, &text.to_be_bytes(), output_format)?;
         }
     }
     Ok(())
 }
+
+fn execute_cipher(
+    operation: OperationChoice,
+    cipher: &impl BlockCipher,
+    text_bytes: &[u8],
+    output_format: Option<OutputFormat>,
+) -> Result<()> {
+    match operation {
+        OperationChoice::Encrypt => {
+            let ciphertext = cipher.encrypt(text_bytes)?;
+            println!("{ciphertext:X}");
+        }
+        OperationChoice::Decrypt => {
+            let plaintext = cipher.decrypt(text_bytes)?;
+            let output = output_format.unwrap_or_default().to_string(&plaintext);
+            println!("{output}");
+        }
+    }
+
+    Ok(())
+}