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6 minute intro
to Fully Homomorphic Encryption (FHE)
Take a deep dive into FHE, the holy grail of cryptography, and how it can solve blockchain confidentiality challenges.
What is Encryption?
Encryption has been used for thousands of years to send secret messages. One early method is the Caesar cipher from 60 BC, which swaps letters in the alphabet.
With the internet, we generate a lot of private data, leading to more data breaches and surveillance. To protect our data, we now use advanced encryption, like end-to-end encryption in everyday apps.
But how does end-to-end encryption work? And how will it change the internet?
Fully Homomorphic Encryption (FHE)
FHE enables data processing without decryption—companies provide services without accessing user data, while users experience unchanged functionality. With encryption maintained during both transit and processing, all online activities can now be truly end-to-end encrypted.
How It Works
Use cloud and blockchain services normally while your data remains completely encrypted. No company, government, or hacker can access your information—same experience, total privacy.
Demos
Try these two demos to understand how FHE works.
These demos below are just for understanding purposes and do not use FHE under the hood. To explore working code, visit docs.zama.org ↗
Step 1 of 4
Pick one of your favourite pictures
Upload a picture to see how a filter can be applied while the image stays fully encrypted throughout.
Step 2 of 4
Create a password to encrypt your picture
Your password ensures the cloud service cannot see the image while processing it. Only you hold the key.
Step 3 of 4
Apply a filter to your encrypted picture
The filter operates on ciphertext. Random pixels in, random pixels out — until you decrypt.
Step 4 of 4
Enter your password to decrypt the result
Decrypt with the same password to reveal your picture with the filter applied — the cloud never saw it.
HOW IT WORKS
Often called the holy grail of cryptography,
FHE is the endgame for bringing confidentiality to blockchain.
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FHE
is composable.
The composability feature of FHE allows for end-to-end confidentiality and programmable onchain privacy without sacrificing interoperability. This enables seamless integration across different blockchain protocols and applications while maintaining data protection.
FHE
is quantum-resistant.
FHE schemes built on lattice-based hardness assumptions are inherently post-quantum resilient, retaining their security even against adversaries equipped with quantum computers. This future-proof cryptographic foundation ensures long-term protection of sensitive data.
FHE
is publicly verifiable.
FHE allows anyone to verify encrypted computations without seeing the underlying data. This trustless verification combines confidentiality with transparency, making it ideal for decentralized systems where auditability matters.
FHE will help onboard the next billion to blockchain
Enabling mass adoption by solving blockchain's transparency problem.
Ultimately, most transactions onchain will become confidential
All payments will become confidential
Transaction amounts and recipient details hidden while maintaining verifiability and compliance.
All wallet balances will become confidential
Account holdings remain private, preventing wealth surveillance and targeted attacks.
Financial institutions will only come to blockchain if confidentiality is guaranteed
Traditional financial institutions require enterprise-grade privacy to meet regulatory and competitive requirements
Government infrastructure will increasingly move onchain
Citizens’ data must remain private — even while enabling public services
Healthcare records, tax information, and identity verification without exposing personal details.
Inter-agency collaboration requires confidential data sharing
Departments can compute on shared datasets without revealing sensitive information to each other.
Regulatory compliance demands auditability without transparency.
Governments need provable compliance, and oversight capabilities while maintaining operational secrecy
Towards a new internet protocol
We believe FHE will enable a new internet protocol, HTTPZ, where everything is encrypted end to end. Privacy wouldn't matter anymore, not because it isn't important, but because it would be guaranteed by design in the internet itself.
No encryption at all, everyone can see everything.
Data is encrypted when sent, but not while processing.
Data is encrypted from end to end, all the time.
Learn more with our 3-minute introductions
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