Patent ID: 8416948

Claim:
A secure variable data rate encryption method, comprising: Receiving blocks of pseudo-random bits of block length K (K>0 and an integer); Receiving a variable data rate packet of length V bits, such that 1<=V<=NK, where N, an integer greater than or equal to 1, is chosen to satisfy NK>=Vmax, where Vmax is the maximum of all variable data rate packet lengths; Appending (NK−V) dummy bits at the end of the said variable data rate packet of length V bits to create an augmented packet of length NK bits, Computing an encrypted ciphertext packet stream by exclusive-or of the augmented packet and N blocks of pseudo-random sequences each of length K bits; Transmitting a first V bits of the encrypted ciphertext after truncating the last (NK−V) bits from the ciphertext of length NK bits.