There was some concern about the security of the product: http://2014.hackitoergosum.org/bittorrentsync-security-privacy-analysis-hackito-session-results/ http

There was some concern about the security of the product: http://2014.hackitoergosum.org/bittorrentsync-security-privacy-analysis-hackito-session-results/ http://2014.hackitoergosum.org/bittorrentsync-security-priva... These concerns were amplified by the difficulty of auditing a closed-source product. Their argument that hashes are one-time secrets and not permanent keys is difficult to validate without access to the source.