✳️ SECURITY | CRYPTOGRAPHY ✳️


‼️ CONCLUSIONS ‼️

▶️ In this work we have shown that Telegram, with its use of aging primitives, does not manage to provide data integrity of ciphertexts nor authenticated encryption, and is vulnerable to chosen-ciphertext attacks.

▶️ The attempt to mitigate known attacks has introduced new vulnerabilities, and we suggest that the Telegram team updates its protocol to use strong, modern primitives.

▶️ For message authentication codes it should use a good HMAC, use a proper key derivation function, and up date the key exchange to use elliptic curve Diffie-Hellman based on Curve25519. Telegram has a great emphasis on computational performance of its protocol, which is why CTR with its parallelization seems to be the logical choice of encryption mode. We suggest using CTR instead of IGE mode, as IGE offers no benefits over CTR.

▶️Overall, we can conclude yet again that homegrown cryptography is a bad approach.

#security #cryptography #cryptanalysis #MTProto