Encryption System

• Light-weight, pseudo-encryption (XOR)

• Could be replaced with real crypto if no impact on RTP stream latency

• XOR pad is a SHA1 hash of a shared secret

• XOR operation is begun at an offset into the hash

• keyhash:

• • sha1(shared-secret)

• keyhash_offset

• • hashword( keyhash, RTP_Seq, RTP_TS ) % 20