There are several books about Venona. The best I've read is "Venona: Decoding Soviet Espionage in America" by John Earl Haynes and Harvey Klehr. The same authors wrote "In Denial: Historians, Communism and Espionage."
In that book they document how, starting in the 1960s, "the study of American Communism was taken over by 'revisionist' historians who attempted to portray the United States as the aggressor in the Cold War and saw the American Communist Party (CPUSA) as an admirable force for promoting denicratuc values."
Further, quoting from the back cover, "Under their (revisionists') influence, the leading historical journals persist in teaching that America's rejection of the Communist Party was a tragic error, that American Communists were actually unsung heroes working for democratic ideals, and that those anticommunist liberals and conservatives who fought against the CPUSA in the 1950s were contemptible."
And that's what your kids learn in college.
“Under their (revisionists’) influence, the leading historical journals persist in teaching that America’s rejection of the Communist Party was a tragic error, that American Communists were actually unsung heroes working for democratic ideals, and that those anticommunist liberals and conservatives who fought against the CPUSA in the 1950s were contemptible.”
In a way, that revisionist statement is actually true... if you define “democratic ideals” as being those from the French Revolution and Reign of Terror in France (since that’s what Marxism derived its actions from).