# Evervault Papers

### Crypto means cryptography

The most important cryptography papers spanning the past, present, and future of cryptosystems & cryptology.

###### On the (Im)possibility of Obfuscating Programs

###### Computer Systems Established, Maintained and Trusted by Mutually Suspicious Groups

###### A Digital Signature Based on a Conventional Encryption Function

###### The Knowledge Complexity of Interactive Proof-Systems

###### Minimal Key Lengths for Symmetric Ciphers to Provide Adequate Commercial Security

###### CryptDB: Protecting Confidentiality with Encrypted Query Processing

###### Protocols for Secure Computations

###### Bitcoin: A Peer-to-Peer Electronic Cash System

###### A fully homomorphic encryption scheme

###### On Data Banks and Privacy Homomorphisms

#### On Data Banks and Privacy Homomorphisms

Ronald L. Rivest, Len Adleman, & Michael L. Dertouzos — Published October 1978

In On Data Banks and Privacy Homomorphisms, Rivest, Adleman, and Dertouzos proposed the problems of (1) modifying a hardware computer system to solve the problem of performing operations on encrypted data securely, and (2) the problem of constructing what has come to be known as a fully-homomorphic encryption (FHE) scheme.

The RSA public-key cryptosystem is a partially homomorphic encryption scheme, where the multiplication of the ciphertext *C* is reflected in the plaintext *P*:

Encrypt P to get C, multiply C by 2, and then decrypt 2C — and you get 2P. That’s a homomorphism: perform some mathematical operation to the ciphertext, and that operation is reflected in the plaintext.” — Bruce Schneier

A FHE cryptosystem is one that is homomorphic under both addition and multiplication and yet still secure. FHE makes it possible to perform arbitrary computations on encrypted data while it remains encrypted — and without needing a secret key. In short, you can process encrypted data without ever decrypting it.

It was not until 2009 when Craig Gentry published a plausible construction of a FHE scheme.

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