implements encrypted metadata support (#63)

* implements encrypted metadata support for every operations

* adds tests for deposiut & withdraw with encrypted metadata

---------

Signed-off-by: Furkan Boyraz <[email protected]>
Co-authored-by: Furkan Boyraz <[email protected]>

Author: BeratOz01

README.md

@@ -15,22 +15,27 @@ AvaCloud API documentation can be found [here](https://docs.avacloud.io/encrypte
 
 ## Key features
 
-- **Confidential Transactions**: User balances and transaction amounts remain completely hidden, ensuring financial privacy.
+- **Confidential Transactions**: User balances and transaction amounts remain completely hidden, ensuring financial confidentiality.
 
 - **Large Integers**: Efficiently handles large token amounts up to 251 bits (2^251), providing greater flexibility.
 
 - **Client-Side Operations**: Users retain control, performing encryption, decryption, and zk-proof generation directly on their own devices.
 
 - **Fully On-chain Nature**: Operates entirely on-chain without the need for relayers or off-chain actors.
 
-- **Built-in Compliance**: Supports external auditors, to ensure regulatory compliance.
 
-- **Dual-Mode Operation**: Supports both standalone tokens and conversion of existing ERC-20 tokens.
+- **Built-in Compliance**: Supports external and rotatable auditors, ensuring regulatory compliance.
 
-- **Zero-Knowledge Proofs**: Uses zk-SNARKs to validate transactions without revealing sensitive information.
+
+- **Dual-Mode Operation**: Supports both creating new private tokens and converting existing ERC-20 tokens their private versions.
+
+- **Zero-Knowledge Proofs**: Uses efficient zk-SNARKs to validate statements without revealing sensitive information.
 
 - **Chain Agnostic**: Can be deployed on any EVM-compatible blockchain.
 
+- **(NEW) Encrypted Metadata**: Allows users to send arbitrary-length encrypted metadata along with transactions.
+
+
 ## Architecture
 
 The eERC protocol consists of several key components:
@@ -82,14 +87,13 @@ The eERC protocol consists of several key components:
 
 1. **Standalone Mode**:
 
-   - Creates entirely new private ERC-20 tokens
-   - Built-in privacy features
-   - Direct token operations
+   - Creates entirely new private ERC-20 (eERC) tokens
+   - Relies on minting and burning to manage token supply
+   - Keeps total supply private all the time, offering better privacy compared to converter mode
 
 2. **Converter Mode**:
-   - Adds privacy features to existing ERC-20 tokens
-   - Wraps existing ERC20 tokens
-   - Enables privacy through deposit/withdraw
+   - Wraps existing ERC20 tokens to eERC tokens
+   - Relies on deposits and withdrawals to manage token supply
    - Maintains compatibility with original tokens
 
 ## File structure
@@ -344,7 +348,6 @@ snarkjs zkey verify <circuit_name>.r1cs powersOfTau28_hez_final_<Size>.ptau <cir
 - For withdraw circuit => `powersOfTau28_hez_final_14.ptau`
 - For registration circuit => `powersOfTau28_hez_final_11.ptau`
 
-
 ## License
 
 This project is licensed under the Ecosystem License - see the LICENSE file for details.