I am writing my Bachelor thesis on topic "Current state of stream ciphers". So my questions is: Which stream ciphers are used the most. So far I have A5 family, RC4, E0 (Bluetooth), Snow 3G and ZUC (5G), Salsa20 family (Chacha20) and block ciphers in some operation modes (OFB, CTR). I am missing whole lightweight cryptography - Ciphers like Grain, Mickey, Trivium (eSTREAM project), but are those really currently used anywhere? What about IP telephony? I read some articles about RC4 used in VoIP but are there any new ciphers? The best thing for my thesis would be to find some new stream ciphers (let's say >2015) which are used in the real environment.

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    $\begingroup$ RC4 is broken, anything still using it is legacy. Your most common (due to TLS) will be ChaCha20-Poly1305 and AES-GCM. $\endgroup$ Apr 30, 2020 at 13:10
  • $\begingroup$ Thank you, Chacha20 is the whole chapter in my work but IFAIK Poly1305 is mac function so its not suitable for my topic. AES-GCM is an operation mode for block cipher so it's not very useful either in my thesis. But anyway, thank I need to be sure that I am not missing something. $\endgroup$ Apr 30, 2020 at 13:34
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    $\begingroup$ AES-GCM is an AEAD stream cipher, using a block cipher core. ChaCha20-Poly1305 is an AEAD stream cipher, using a permutation core. Both are stream ciphers. Using AES-CTR alone isn't recommended, since it's malleable. Same with ChaCha20 alone. So neither will be that common, since most libraries don't do that by default. And TLS thus doesn't include them. Since that's the most common use of encryption right now, looking at what it provides (AES-GCM, AES-CCM, ChaCha20-Poly1305 for 1.3, also some CBC+HMAC for 1.2 but those aren't stream ciphers) is a good starting point. $\endgroup$ Apr 30, 2020 at 13:44
  • $\begingroup$ I don't agree with above. The tag is not part of the key stream, so I don't consider AES-GCM to be just a stream cipher. I expect a stream cipher to be online and perform byte-to-byte encryption and decryption. This is not entirely the case if the tag is used as part of it. AES in counter mode is used directly in AES-GCM - now that is a stream cipher, but it was already included. $\endgroup$
    – Maarten Bodewes
    Apr 30, 2020 at 17:35
  • $\begingroup$ I came across stream cipher Crypto-1 which is "a proprietary encryption algorithm created by NXP Semiconductors specifically for Mifare RFID tags, including Oyster card, CharlieCard and OV-chipkaart." Crypto-1 This is therefore the currently used stream cipher $\endgroup$ May 5, 2020 at 14:38


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