Limited Direct Compatibility with Mobile Devices

• Traditional USB DSC tokens are primarily designed for desktop and laptop use.
  
• Most mobile phones do not have standard USB ports or require drivers.
  
• Direct use of USB DSC tokens on mobile devices is generally not supported.
  
• Mobile operating systems do not natively recognize cryptographic token drivers.
  
• Compatibility is limited due to hardware and software restrictions.
  

Workarounds Using OTG and Smart Tokens

• Some USB tokens may work with Android devices using OTG (On-The-Go) adapters.
  
• The mobile device must support OTG and the necessary cryptographic libraries.
  
• Even with OTG, special apps or configurations are required.
  
• iOS devices typically do not support external DSC tokens.
  
• Use is limited and may not be reliable for secure transactions.
  

Cloud-Based and Remote DSC Solutions

• Mobile-compatible alternatives include cloud-based or server-based DSC solutions.
  
• These allow users to sign documents through secure remote authentication.
  
• The private key is stored on a central server, not a physical token.
  
• Users authenticate using mobile credentials such as OTP or biometrics.
  
• This is increasingly adopted in mobile-friendly government and enterprise portals.
  

App-Integrated Signing Solutions

• Some digital signature service providers offer mobile apps for document signing.
  
• These apps support signing via cloud DSC or remote certificate validation.
  
• The user accesses the certificate securely through mobile login.
  
• It eliminates the need for physical USB tokens.
  
• Such solutions meet legal and IT Act requirements if properly certified.
  

Security and Compliance Considerations

• Cloud and mobile DSC solutions must be licensed and approved under the IT Act.
  
• They must ensure the same level of encryption, integrity, and non-repudiation.
  
• Proper authentication controls must be in place to prevent misuse.
  
• Regulatory compliance and audit trails are essential for legal validity.
  
• Users should avoid unofficial tools that compromise security.