Secure blockchain-controlled digital signatures with post-quantum-ready security.




Your Digital Signature, Simplified.

Secure. Simple. Signed.

Our Services

Blockchain-secured e-signatures with verified ID and location.

PDF Digital Blockchain Signature

PDF Digital Blockchain Signature

We provide a modern, tamper-proof way to sign PDF documents using blockchain technology. Each signature is encrypted, timestamped, and written to the blockchain, creating a permanent and verifiable record that cannot be altered. Whether you’re signing a single contract or managing multi-party agreements, our system ensures that every signature is authentic, legally valid, and easy to verify.

KYC ID & Location Verification

KYC ID & Location Verification

Verify customer identity with secure ID document checks, live geolocation capture, and audit-ready evidence.

Optional video chat provides real-time presence and liveness verification, with transcripts and artifacts stored for compliance.

Secure document storage Amazon S3 Bucket

Secure document storage Amazon S3 Bucket

Amazon Simple Storage Service (S3) is a highly durable, scalable object storage service. XSigi uses S3 buckets to securely store your encrypted documents with fine-grained access control, server-side or client-side encryption, versioning, and lifecycle policies to retain what you need and purge what you don't.

TEXT Encryption

TEXT Encryption

Use the new XSigi Envelope v1 format for text encryption combining three powerful cryptographic techniques:

  • Ed25519 signature — ensures authenticity & integrity, letting recipients verify the sender.
  • X25519 sealed boxes — provides confidentiality so only the intended recipient can decrypt.
  • Armored JSON — wraps encrypted data in readable JSON for easy transport & embedding.

Together, they deliver a portable, verifiable, and secure text container ready for modern workflows.

CRYSTALS-Kyber: The Key to Post-Quantum Encryption

CRYSTALS-Kyber: The Key to Post-Quantum Encryption

Deploy lattice-based, NIST-selected CRYSTALS-Kyber for fast, quantum-resistant key encapsulation securing documents and secrets against future attacks.

  • Quantum-resistant key exchange
  • Low bandwidth, high performance
  • Future-proof secure workflows

Integrated into XSigi’s encryption pipeline to protect data today—and after large-scale quantum computers arrive.

Invisible Watermark (DCT-based)

Invisible Watermark (DCT-based)

Protect your images with an invisible, tamper-resistant watermark that leverages Discrete Cosine Transform (DCT) technology. Unlike visible overlays, a DCT-based watermark is hidden within the frequency domain of the image, making it imperceptible to the human eye but reliably detectable with the right tools.

It’s ideal for photographers, designers, and businesses that need to prove ownership without altering visual quality.

ZIP Encryption

ZIP Encryption

Protect your files with next-generation encryption that combines public/private key technology and the ChaCha20-Poly1305 algorithm, delivering both speed and uncompromising security. This advanced method ensures that only the intended recipient can unlock the contents of your ZIP file, while every attempt at tampering is immediately detectable.

Contract Designer

Contract Designer

Create professional, legally-binding contracts with our intuitive drag-and-drop designer. Build custom templates with your branding, define signature fields, add clause libraries, and manage multi-party agreements—all with built-in cryptographic signing and tamper-proof audit trails.

How XSigi works

Not a fan of reading? No worries — our Video Explainer section has you covered!





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