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For encryption and decryption of the data flow (and hence for providing confidentiality of the data flow), we use AES128-CM as the a default cipher that is commonly used for SRTP.
To authenticate the message, protect its integrity, and to provide replay protection, we use the HMAC-SHA1 algorithm (defined in RFC 2104). This produces a 160-bit result, which is then truncated to 80 bits to become the authentication tag appended to the packeta standard security algorithm.
To securely establish the keys for all of the above, we use Datagram Transport Layer Security (DTLS).
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