Abstract: A method for authenticating a user identity asserted from a client device may include receiving information that asserts a user identity including a user identifier, accessing external data stores to receive data rows that are associated with the user identity, and accessing monitoring systems to receive data vectors. The monitoring systems may monitor transmissions to receiving systems, the data vectors may include numerical target values for the receiving systems, and the data vectors may be accessed using the user identifier. The method may also include determining whether the data rows can be matched to the data vectors, and based on that determination, authenticating the user identity.

Abstract: A method of verifying a challenge value may include receiving the challenge value from a client device; accessing an external data store to receive data rows that may be associated with a user of the client device; filtering data rows that are not sourced from computer systems associated with the challenge value; grouping the data rows into groups based on which of the computer systems each of the data rows were sourced; determining an input velocity for each of the groups; determining an interval value for each of the groups based on the input velocity; calculating a group value for each of the groups based on the interval value and the input velocity; calculating an estimated total value based on the group values; and determining whether the challenge value can be verified by determining whether the estimated total value is within a threshold of the challenge value.