# Comparison of SSI Agent Solutions

## Comparison Table

| Feature | Custodial Solution | Non-Custodial Solution | Hybrid Solution |
|-----------------------------|-------------------------------------------------|-----------------------------------------------|------------------------------------------------|
| **Control of Identity Data**| Service provider controls the identity data. | User has full control over their identity data.| Shared control between the user and provider. |
| **Data Accessibility** | Data is stored centrally. | Data is stored on user's device or chosen location.| Data is encrypted and stored both locally and potentially backed up by the provider. |
| **Risk of Data Breach** | Higher, due to centralized data storage. | Lower, as data is dispersed and under user control.| Reduced risk through data distribution and encryption. |
| **Recovery of Credentials** | Easier, as the provider can assist in recovery. | More challenging, relies on user's backup solutions.| Enhanced recovery options compared to non-custodial. |
| **User Convenience** | Generally higher, less technical burden on user.| Requires more technical awareness and management.| Balances convenience with a degree of user control. |
| **Portability** | Dependent on the provider's infrastructure. | More portable, as data can be moved freely. | Aims to combine portability with support. |
| **Dependency** | Dependent on the service provider's availability and integrity.| Less dependency, as the user maintains control.| Partial dependency on the service provider. |

## Custodial Solution

### Pros

1. **Ease of Use:** Users find custodial solutions straightforward as they do not need to directly manage keys or data.
2. **Recovery Options:** Service providers can assist with data recovery, reducing the risk of permanent loss.
3. **Lower Technical Barrier:** Accessible to users without advanced technical knowledge.

### Cons

1. **Control and Surveillance:** Providers control users' identity data, raising potential surveillance or misuse issues.
2. **Risk of Data Breach:** Centralized data storage can be a lucrative target for hackers.
3. **Dependence on Provider:** Users must trust the provider's integrity and security practices.

## Non-Custodial Solution

### Pros

1. **Full Control:** Users maintain complete control over their identity data, enhancing privacy.
2. **Reduced Breach Risk:** Decentralized data storage lowers mass breach susceptibility.
3. **Portability:** Users can freely transfer their identity data across services or devices.

### Cons

1. **Technical Requirement:** Users must manage their keys and data, requiring technical know-how.
2. **Recovery Responsibility:** Users are responsible for their data and key recovery.
3. **User-Friendliness:** Self-management can make these solutions less intuitive for non-technical users.

## Hybrid Solution

### Pros

1. **Balanced Control:** Offers a mix of user control and provider support.
2. **Enhanced Recovery:** Provides robust recovery options without full data exposure.
3. **User-Friendly:** Balances technical demands with an intuitive user experience.

### Cons

1. **Complexity:** Balancing control, security, and usability adds complexity.
2. **Partial Provider Trust:** Users still need to trust the provider for certain services.
3. **Compromise Potential:** May inherit limitations and vulnerabilities of both models.