ENCRYPTION

Contents

Symmetric encryption

DES and 3DES

DES: FIPS 81, DES/3DES FIPS 46-3

AES

Asymmetric encryption of symmetric keys

Asymmetric encryption

RSA encryption

Based on the difficulty of factorisation.

ECC encryption

Based on the difficulty of DLP on an elliptic curve.

Pairing-base encryption

Is a variant of elliptic curve cryptography, where a pairing is a special map defined over elliptic curves. Generally, elliptic curves is defined so that pairing is not efficiently computable since elliptic curve cryptography is broken if pairing is efficiently computable. As the importance of pairing grows, elliptic curves where pairing is efficiently computable are studied and the special curves called pairing-friendly curves are proposed. Thanks to the characteristics of pairing, it can be applied to construct several cryptographic algorithms and protocols such as identity-based encryption (IBE), attribute-based encryption (ABE), authenticated key exchange (AKE), short signatures and so on.

NTRU encryption

NTRU is an open source public-key cryptosystem that uses lattice-based cryptography to encrypt and decrypt data. It consists of two algorithms: NTRUEncrypt, which is used for encryption, and NTRUSign, which is used for digital signatures. Unlike other popular public-key cryptosystems, it is resistant to attacks using Shor's algorithm. NTRUEncrypt was patented, but it was placed in the public domain in 2017. NTRUSign is patented, but it can be used by software under the GPL.

NTRU is an abbreviation for "Nth degree truncated polynomial ring units."

XTR encryption

XTR is an algorithm for public-key encryption, relying on the difficulty of the DLP. XTR stands for 'ECSTR', which is an abbreviation for Efficient and Compact Subgroup Trace Representation. It relies on the difficulty of solving Discrete Logarithm related problems in the full multiplicative group of a finite field. Unlike many cryptographic protocols that are based on the generator of the full multiplicative group of a finite field, XTR uses the generator g of a relatively small subgroup of some prime order q of a subgroup.

Authenticated encryption

Authenticated encryption (AE) and authenticated encryption with associated data (AEAD) are forms of encryption which simultaneously assure the confidentiality and authenticity of data.

Six different authenticated encryption modes (namely OCB 2.0, Key Wrap, CCM, EAX, Encrypt-then-MAC (EtM), and GCM) have been standardized in ISO/IEC 19772:2009. More authenticated encryption methods were developed in response to NIST solicitation.

Basics

Homomorphic encryption

Homomorphic encryption is a form of encryption that allows computation on ciphertexts, generating an encrypted result which, when decrypted, matches the result of the operations as if they had been performed on the plaintext.

Basics

Systems

MPC

Secure multi-party computation (also known as secure computation, multi-party computation (MPC), or privacy-preserving computation) is a subfield of cryptography with the goal of creating methods for parties to jointly compute a function over their inputs while keeping those inputs private. Unlike traditional cryptographic tasks, where cryptography assures security and integrity of communication or storage and the adversary is outside the system of participants (an eavesdropper on the sender and receiver), the cryptography in this model protects participants' privacy from each other.

Related to Shamir's 'How to share a secret'.

Basics

Lightweight Cryptography (LWC)

Functional encryption

Functional encryption (FE) is a generalization of public-key encryption in which possessing a secret key allows one to learn a function of what the ciphertext is encrypting.