15. A tangible, non-transitory, machine-readable medium storing instructions that when executed by one or more processors effectuate operations comprising: obtaining a multi-byte character set specifying a plurality of characters; receiving a knowledge factor credential encoded with a plurality of characters of the multi-byte character set, wherein the knowledge factor credential has a longer effective length than an apparent length, and wherein the knowledge factor credential has at least one character outside of a block of characters designated for a locale of the computing device, wherein receiving the knowledge factor credential comprises: retrieving from memory candidate characters based on a user previously designating the candidate characters; presenting a user interface by which the candidate characters are selectable, wherein presenting a user interface by which the candidate characters are selectable comprises interspersing the candidate characters among un-designated characters to obfuscate which characters were previously designated; receiving a user selection of at least one of the candidate characters; and providing the knowledge factor credential to authenticate a user.
15. A tangible, non-transitory, machine-readable medium storing instructions that when executed by one or more processors effectuate operations comprising: obtaining a multi-byte character set specifying a plurality of characters; receiving a knowledge factor credential encoded with a plurality of characters of the multi-byte character set, wherein the knowledge factor credential has a longer effective length than an apparent length, and wherein the knowledge factor credential has at least one character outside of a block of characters designated for a locale of the computing device, wherein receiving the knowledge factor credential comprises: retrieving from memory candidate characters based on a user previously designating the candidate characters; presenting a user interface by which the candidate characters are selectable, wherein presenting a user interface by which the candidate characters are selectable comprises interspersing the candidate characters among un-designated characters to obfuscate which characters were previously designated; receiving a user selection of at least one of the candidate characters; and providing the knowledge factor credential to authenticate a user. 19. The medium of claim 15 , wherein receiving the knowledge factor credential comprises: presenting a user interface through which more than 4,096 characters are selectable.