Is encryption really necessary for the operation of the blockchain?

Is it fair to say that Bitcoin and other blockchains do not use encryption? I've read somewhere that blockchains rely on digital signatures and hash functions but not on encryption, and that encryption is only used on the client side (eg, cryptographic portfolios) … But it seems that encryption is also part of these other cryptographic techniques … So, I'm not sure. m trying to clarify whether blockchain technology requires encryption or not. Thank you!