I am working with the COSMIC data extracts, specifically the UCSC Mutation Export, available at: ftp://ftp.sanger.ac.uk/pub/CGP/cosmic/data_export/Request_based_exports/UCSCMutExp_v66_250713.csv.gz
I am using the mutation locations in the file and then looking them up in the UCSC database. I noticed there is a FASTA archive hosted in the COSMIC ftp site. Should I be using this instead of the hg19.2bit file available from UCSC, or is the data the same? ftp://ftp.sanger.ac.uk/pub/CGP/cosmic/fasta.tgz
edit Related question: Applying SNP masking in primer creation
If they contain the same info, the hashes will be identical.
You might want to ask the COSMIC folks what they recommend, see http://cancer.sanger.ac.uk/cancergenome/projects/cosmic/contact