## public key cryptography [English]

### Syndetic Relationships

### InterPARES Definition

No definition in earlier IP projects. ITrust definition not yet developed.

### Other Definitions

- Diffie & Landau 2007 (†848 p.397): cryptography in which communications are controlled by two keys, one of which can be made public without revealing the other. Public key cryptography makes it possible to separate the capabilities for encrypting and decrypting.
- DuPont 2016 (†854 p.295): two mathematically linked keys can be used for complex multi-pass encryption schemes (such as the Diffie-Hellman key exchange). … [Originally] called “non-secret” encryption...

### Citations

- Chuen (ed) 20156 (†855 p.21): Central to Bitcoin technology is public-key cryptography, which with the SHA-256 hash function is used to generate Bitcoin addresses, sign transactions, and verify payments. Public-key cryptography is a technique of reliably determining the authenticity of Bitcoin transactions using digital signatures. It uses an asymmetrical algorithm that generates two separate but asymmetrically linked keys: a public key and a private key. The keys are asymmetrical in the sense that the public key is derived from the private key but it is computationally impossible to obtain a private key from a public key. (†2384)
- de Leeuw et al. (eds) 2007 (†850 p.576): As the keys for encryption and decryption are different, and Alice and Bob have different information, public-key algorithms are also known as asymmetric algorithms. (†2380)
- Diffie & Landau 2007 (†848 p.644): In a public key cryptosystem enciphering and deciphering are governed by distinct keys, E and D, such that computing D from E is computationally infeasible (e.g., requiring 10100 instructions). The enciphering key E can thus be publicly disclosed without compromising the deciphering key D. Each user of the network can, therefore, place his enciphering key in a public directory. This enables any user of the system to send a message to any other user enciphered in such a way that only the intended receiver is able to decipher it. (†2373)
- Diffie & Landau 2007 (†848 p.39): In a public-key cryptosystem, every message is operated on by two keys, one used to encipher the message and other to decipher it…. The keys are inverses in that anything encrypted by one can be decrypted by the other. However, given access to one of these keys, it is computationally infeasible to discover the other one. (†2374)