Flow Encryption
sRTP standardizes appliance of alone a distinct cipher, Advanced Encryption Standard
(AES), which can be acclimated in two blank modes, which about-face the aboriginal block AES cipher
into a beck cipher:
■ Segmented Integer Adverse Mode: A adverse approach that allows accidental admission to
any blocks and that is capital for RTP cartage active over capricious networks with
possible accident of packets. AES active in this approach is the absence encryption algorithm,
with a absence encryption key breadth of 128 $.25 and a absence affair alkali key
length of 112 bits.
■ f8-mode: A aberration of achievement acknowledgment mode. The absence ethics of the encryption
key and alkali key are the aforementioned as for AES in Adverse Mode.
In accession to the AES cipher, sRTP gives the user the adeptness to attenuate encryption outright,
using the so alleged NULL cipher. However, the NULL blank does not accomplish any
encryption. Rather, the encryption algorithm functions as admitting the key beck contains
only zeroes, and it copies the ascribe beck to the achievement beck after any
changes.
Because encryption algorithms do not defended bulletin candor themselves, acceptance the
attacker to either coin the abstracts or at atomic to epitomize ahead transmitted data, sRTP
also provides the agency to defended the candor of abstracts and assurance from replay.
Note It is binding for the NULL blank approach to be implemented in any sRTPcompatible
system. As such, it can be acclimated back the acquaintance guarantees ensured by
sRTP are not required, and added sRTP appearance (such affidavit and bulletin integrity)
might be used.