# Which cipher is used in the new 5G network?

I think that the stream ciphers SNOW 3G and AES are used in 4G (LTE). But I can't find which cipher is used in 5G networks and how encryption is done. Is there any official documentation?

• I don't know. But there is a chance that some answers are here. What about combing that then posting an answer to your own question? I'd upvote Q&A.
– fgrieu
Apr 20 '20 at 16:32

## 1 Answer

Ericson's white paper lists them as

The strong and well-proven security algorithms from the 4G system are reused. These are encryption algorithms based on SNOW 3G, AES-CTR, and ZUC; and integrity algorithms based on SNOW 3G, AES-CMAC, and ZUC. The main key derivation function is based on the secure HMAC-SHA-256.

Notably, all of them are stream ciphers as CTR mode converts any block cipher into a stream cipher.

• SNOW 3G is a word-based synchronous stream cipher developed by Thomas Johansson and Patrik Ekdahl at Lund University.
• ZUC uses a 16-stage LFSRs with each stage in $$GF(2^{31}-1)$$ and produces a 32-bit word on each tick.
• With the word size being specified as 32 bit for SNOW 3G in case you're wondering. Word is short for "machine word" so the size is kind of unknown unless you specify a machine. Jun 7 '20 at 9:50