Instant messaging is a prevalent form of communication across the Internet, yet most instant messaging services provide little security against eavesdroppers or impersonators. There are a variety of existing systems that aim to solve this problem, but the one that provides the highest level of privacy is Off-the-Record Messaging (OTR), which aims to give instant messaging conversations the level of privacy available in a face-to-face conversation. In the most recent redesign of OTR, as well as increasing the security of the protocol, one of the goals of the designers was to make OTR easier to use, without users needing to understand details of computer security such as keys or fingerprints.

A numerical investigation is presented for the peak sidelobe level (PSL) of Legendre sequences and maximal length shift register sequences (m-sequences). The PSL gives an alternative to the merit factor for measuring the collective smallness of the aperiodic autocorrelations of a binary sequence. The growth of the PSL of these infinite families of binary sequences is tested against the desired growth rate o(radic(n ln n)) for sequence length n. The claim that the PSL of m-sequences grows like O(radicn), which appears frequently in the radar literature, is concluded to be unproven and not currently supported by data. Notable similarities are uncovered between the PSL and merit factor behaviour under cyclic rotations of the sequences

A numerical investigation is presented for the peak sidelobe level (PSL) of Legendre sequences, maximal length shift register sequences (m-sequences), and Rudin-Shapiro sequences. The PSL gives an alternative to the merit factor for measuring the collective smallness of the aperiodic autocorrelations of a binary sequence. The growth of the PSL of these infinite families of binary sequences is tested against the desired growth rate o(/spl radic/nlnn) for sequence length n. The claim that the PSL of m-sequences grows like O(/spl radic/n), which appears frequently in the radar literature, is concluded to be unproven and not currently supported by data. Notable similarities are uncovered between the PSL and merit factor behavior under cyclic rotations of the sequences.