# Key Features

Proto-USD acts as a superset of CCTP by offering the same functionality while providing additional perks that are not present in CCTP. See below:

<figure><img src="https://4144361836-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FyXM6bEIC9hOjfFsdiXGc%2Fuploads%2FmJfEisPbqjBGJ1AWNuwf%2Fimage.png?alt=media&#x26;token=e57d59a3-e679-40cc-bc27-261fe50fd327" alt="" width="563"><figcaption></figcaption></figure>

## Bridged USDC Support

Proto-USD enables the transfer of Bridged USDC and Custom USDC across blockchains, making it possible for networks without native USDC to participate in cross-chain liquidity flows.

| USDC Type    | Issuer of USDC                              | Proto-CCTP Eligibility |
| ------------ | ------------------------------------------- | ---------------------- |
| Bridged USDC | USDC from Circle Bridged Standard contracts | Yes                    |
| Native USDC  | Circle issued                               | Yes                    |
| Custom USDC  | Rollups, built-in from zkEVM, etc.          | Yes                    |

<br>

## Multi-Hop Messaging

Proto-USD relays cross-chain messages through multiple blockchains. See below for how the multi-hop message system works.&#x20;

**Polygon <--> Arbitrum**

Proto utilizes CCTP for all USDC transfers on existing CCTP-enabled blockchains.<br>

<figure><img src="https://4144361836-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FyXM6bEIC9hOjfFsdiXGc%2Fuploads%2FVFsr5tn5vk5KhScCvcQ6%2Fimage.png?alt=media&#x26;token=91abf21a-f162-4ee8-b68e-cbc08284be1a" alt="" width="563"><figcaption></figcaption></figure>

**Polygon <--> Arbitrum <--> Blockchain X**

If a user on Blockchain X has USDC on Polygon in their wallet, Proto-USD will burn the native USDC on Polygon, mint native USDC on Arbitrum, and then wrap native USDC on Arbitrum and mint Bridged Standard USDC on Blockchain X – completing the transfer.  &#x20;

From the user’s standpoint, the multi-hopping of transactions is abstracted. The USDC transfer “just works”.

<figure><img src="https://4144361836-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FyXM6bEIC9hOjfFsdiXGc%2Fuploads%2F5voi5JiWXlq1ydnfqtFP%2Fimage.png?alt=media&#x26;token=2fea5c75-d4b4-4591-a362-3dcb043a9ae9" alt=""><figcaption></figcaption></figure>

**Blockchain Y <--> Polygon <--> Arbitrum <--> Blockchain X**

The most complex example (and further extension of the above) shows two blockchains with the Bridged USDC Standard being able to transfer USDC between each other. This is possible because all Bridged Standard USDC is sourced 1:1 from a CCTP-enabled blockchain.

<figure><img src="https://4144361836-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FyXM6bEIC9hOjfFsdiXGc%2Fuploads%2FZQOQdIKOzVNuf5lIdVxP%2Fimage.png?alt=media&#x26;token=fa0e596e-d689-4748-ba6d-9b62bce9a6e3" alt=""><figcaption></figcaption></figure>

## Value + Data Transfers

With Proto-USD, USDC + data can be sent in the same cross-chain transaction. Opening up the possibility for dapps to develop protocols using advanced liquidity sourcing methods such as cross-chain staking, cross-chain lending/borrowing, cross-chain swap routers, etc.

<figure><img src="https://4144361836-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FyXM6bEIC9hOjfFsdiXGc%2Fuploads%2FXMmekPgb69h8ZqrMxcSr%2Fimage.png?alt=media&#x26;token=b5709cc0-5418-4971-9792-0ecd34764463" alt="" width="563"><figcaption><p>USDC + Data sending over Proto-CCTP</p></figcaption></figure>

## Layered Security

The phrase “Not your keys, not your crypto” is just as relevant to cross-chain messaging: “Not your keys, not your messages.” With the VIA Network’s layered security architecture, blockchain foundations have the ability to run their own validation layer, similar to Circle’s IRIS attestation network. This allows blockchains to take control of their message security, ensuring the highest level of protection.