No, you need to learn cryptography if you are going to learn about Blockchain. Cryptography, Peer to Peer Technology are the building blocks of the blockchain technology. If you don't have a strong insight on these two, you will have a very tough time on mastering the technology. You need to note that, very few are interested in learning the tech since most of them are driven by the cryptocurrency hype you will find a way in paving your future if you master this technology to quite an extent and start developing some simple dapps.

Blockchain can simply be called as a data structure or more commonly a digital asset. For you to protect your physical assets you require hard cases, lockers and keys. Similarly cryptography helps you in protecting your digital asset/datas. Without learning how to protect these datas, managing these confidential records in the digital form are quite useless. Further you need to understand that this cryptography was primary in securing the multi billion dollar cryptocurrency market. They can secure your records provided how safely you handle the private keys. If you have learnt about cryptography and a good code, it is up-to you to how effectively you use them to manage your records.