Ethical Wall (Information Barrier)

An ethical wall, also called an information barrier or screen, is a set of controls that stops confidential information held by one group inside a firm from reaching another group that must not have it. In US broker-dealers it is how firms meet Section 15(g) of the Securities Exchange Act, which requires written policies reasonably designed to prevent misuse of material nonpublic information (MNPI). In law firms it is the "screen" in ABA Model Rule 1.0(k), which under Rule 1.10 can keep a laterally hired lawyer's conflict from being imputed to the whole firm.

In identity terms an ethical wall is an access policy with a business reason attached. Bankers on the private side of a deal and traders on the public side get disjoint entitlements to deal rooms, document stores, chat channels and data feeds; a screened lawyer is denied access to the matter's files, which the ABA commentary says includes information in electronic form. Enforcement usually combines RBAC for the private and public side groups, ABAC for deal-level or matter-level attributes, and segregation of duties rules that block the conflicting combination at request time. The SEC's 2012 staff report on information barriers flagged "above-the-wall" roles that receive MNPI with few controls, and listed reviewing access reports for electronic information services, and blocking public-side staff from them until authorized, among the effective practices it observed. Logged, reviewable access decisions are what turn the wall from a memo into evidence.

See also: segregation of duties, ABAC, least privilege, financial services identity, access certification