SQL Server 2012 :: Find Common Link Between Two Tables In Database Without Key Constraints?

CREATE TABLE [Table 1] (
Id varchar,
TableTwoId varchar,
OtherData varchar )
CREATE TABLE [Table 2] (
Id varchar,
MoreData varchar )

What is the link between these two tables?

I have databases that have zero keys defined, no foreign key constraints, no unique value constraints. I cannot assume that an Identity column is the Id. The end game is be able to output that [Table 1].[TableTwoId] = [Table 2].[Id] but cannot assume that all linkage in the database will be as simple as saying "if the field name contains a table name + Id then it is the Id in that table."

Currently have written a script that will cycle through all columns and start identifying keys in singular tables based on the distinctness of the values in each column (i.e. Column1 is 99% distinct so is the unique value). It will also combine columns if the linkage is the combination of one or more columns from Table 1 = the same number of columns in Table 2. This takes a long time, and it somewhat unreliable as IDENTITY columns may seem to relate to one another when they don't.